Inulin clearance is the gold standard for GFR because inulin is freely filtered, not reabsorbed or secreted.

Serum creatinine is routinely used to estimate GFR and renal function.

Proteinuria >3.5 g/day is the hallmark of nephrotic syndrome.

Urine dipstick is sensitive to albumin but misses light chains and globulins.

Renal ultrasound is non-invasive, radiation-free, and excellent for assessing kidney size, cortical thickness, and hydronephrosis.

Periorbital edema in the morning is classic for nephrotic syndrome due to low oncotic pressure and gravity redistribution overnight.

Dependent edema worsening by evening is classic for congestive heart failure due to gravity.

Loss of albumin in urine decreases plasma oncotic pressure, causing fluid to shift to interstitium.

Renal edema starts in face/periorbital area (loose tissue), while cardiac edema is dependent (legs/sacrum).

Hypothyroidism causes myxedema–non-pitting edema due to glycosaminoglycan accumulation.

Minimal change disease accounts for 70–90% of nephrotic syndrome in children under 10 years.

Foot process effacement (fusion) is the hallmark on EM.

Minimal change disease is highly steroid-responsive (>90% remission).

Immunofluorescence is negative in MCD–no immune complex deposition.

Viral URTIs commonly trigger MCD episodes in children.

PSGN occurs 1–3 weeks after pharyngitis or 3–6 weeks after skin infection.

Nephritic syndrome presents with hematuria (cola-colored urine), hypertension, and edema.

Anti-DNase B is elevated after skin infections (impetigo).

C3 is consumed due to immune complex-mediated complement activation in PSGN.

PSGN shows diffuse endocapillary proliferation with neutrophil infiltration.

Subepithelial dome-shaped “humps” are pathognomonic for PSGN.

Children with PSGN have excellent prognosis–>95% recover completely.

Episodic gross hematuria occurring within 1–2 days of URTI is classic (“synpharyngitic hematuria”).

IgA nephropathy (Berger disease) is the most common primary GN globally.

Mesangial IgA deposition is diagnostic.

Complement levels remain normal in IgA nephropathy (alternative pathway not significantly activated).

HSP is the systemic form of IgA nephropathy with skin purpura, arthritis, GI symptoms, and nephritis.

Chronic GN and FSGS are leading causes of ESRD from primary GN.

Chronic GN leads to bilateral small, scarred kidneys due to nephron loss and fibrosis.

Increased cortical echogenicity indicates chronic parenchymal damage and fibrosis–irreversible.

Hyponatremia is the most common electrolyte disorder, often due to IV fluids, medications (diuretics), or SIADH.

Peaked (tall, tented) T waves are the earliest ECG sign of hyperkalemia.

Calcium gluconate stabilizes cardiac membrane immediately but doesn’t lower potassium.

U waves (after T waves) are classic for hypokalemia, along with flattened T waves and ST depression.

Facial muscle twitching on tapping facial nerve indicates hypocalcemia (neuromuscular irritability).

Carpal spasm occurring within 3 minutes of BP cuff inflation (above systolic) indicates hypocalcemia.

Primary hyperparathyroidism is the most common outpatient cause.

Hypercalcemia causes nephrogenic diabetes insipidus (polyuria), altered mental status, and constipation.

Low pH with high PaCO2 and normal HCO3 indicates uncompensated respiratory acidosis (CO2 retention).

DKA produces ketoacids causing high anion gap acidosis (MUDPILES).

Hyperventilation from anxiety blows off CO2, causing respiratory alkalosis.

Lungs compensate for metabolic alkalosis by retaining CO2 (hypoventilation).

Deep, rapid Kussmaul respirations compensate for metabolic acidosis by eliminating CO2.

Oliguria is <400 mL/day (or <0.5 mL/kg/hr).

Prerenal azotemia shows BUN:Cr >20:1 due to increased urea reabsorption in hypoperfusion.

FeNa <1% indicates avid sodium retention by functioning tubules in prerenal azotemia.

ATN from ischemia or nephrotoxins is the most common inpatient AKI cause.

Muddy brown granular casts are pathognomonic for ATN (sloughed tubular cells).

Asterixis (flapping tremor) is characteristic of metabolic encephalopathies including uremia.

In severe uremia, urea in sweat crystallizes on skin creating a “frosted” appearance.

Pericardial friction rub (scratchy sound) is the hallmark of uremic pericarditis.

Intensive dialysis is the definitive treatment–removes uremic toxins.

CKD requires kidney damage or GFR <60 mL/min persisting for ≥3 months.

Diabetic nephropathy is the leading cause of CKD and ESRD globally.

Stage 4 = GFR 15–29 (severely decreased).

Kidneys produce erythropoietin; loss of renal mass reduces EPO → normocytic anemia.

CKD causes phosphate retention (reduced excretion) and decreased 1,25-dihydroxyvitamin D (less 1-alpha hydroxylation), leading to hypocalcemia and compensatory PTH elevation.

Renal osteodystrophy encompasses bone disorders from CKD mineral disturbances (high PTH, low vitamin D, high phosphate).

Glomerular bleeding causes dysmorphic (irregular) RBCs and RBC casts due to passage through GBM.

RBC casts form in tubules when RBCs from glomeruli are trapped in protein matrix–indicates GN.

Painless gross hematuria in older adults is bladder cancer until proven otherwise.

Urinalysis with microscopy is the first step–identifies source (glomerular vs non-glomerular), infection, casts.

Fever, costovertebral angle tenderness/flank pain, and pyuria/bacteriuria define upper UTI (pyelonephritis).

coli causes 80–85% of community-acquired UTIs.

Sterile pyuria occurs in TB (mycobacteria don’t grow on routine culture), viral infections, malignancy, interstitial nephritis, and recently treated UTI.

Systemic symptoms (fever >38°C) and costovertebral angle tenderness indicate upper tract infection.

≥10^5 CFU/mL is significant bacteriuria confirming UTI.

Fluoroquinolones have excellent tissue penetration and cover most uropathogens.

Complicated pyelonephritis (obstruction, abscess, sepsis, pregnancy, diabetes) needs IV antibiotics and hospitalization.

Acute prostatitis has fever, severe perineal/pelvic pain, dysuria, and exquisitely tender, boggy prostate on exam.

coli and other Enterobacteriaceae cause most bacterial prostatitis cases.

Chronic prostatitis has symptoms persisting or recurring ≥3 months.

Vigorous prostatic massage can release bacteria into bloodstream causing bacteremia/sepsis.

Gram-negative intracellular diplococci (kidney bean-shaped, within neutrophils) are pathognomonic for gonorrhea.

Chlamydia trachomatis is the most common bacterial STI globally.

Herpes causes painful, multiple vesicles/ulcers with tender lymphadenopathy.

The syphilitic chancre is painless, indurated (hard), clean-based ulcer at inoculation site.

Dual therapy (ceftriaxone 500 mg IM + azithromycin 1 g PO) covers both organisms and combats resistance.

Varicocele (dilated pampiniform plexus) is found in 35–40% of infertile men–impairs spermatogenesis via increased scrotal temperature.

Azoospermia = no sperm in ejaculate (can be obstructive or non-obstructive).

Growth hormone (GH) and prolactin are secreted by acidophils (somatotrophs and lactotrophs).

Prolactinomas account for approximately 40–50% of all functioning pituitary adenomas.

The optic chiasm lies directly above the pituitary gland.

Excess GH before epiphyseal plate closure causes proportionate tall stature (gigantism).

Normally, glucose suppresses GH to <1 ng/mL.

Sheehan syndrome is ischemic necrosis of the enlarged pituitary following postpartum hemorrhage and hypotension.

The typical order of hormone loss is GH → LH/FSH → TSH → ACTH.

Bromocriptine (or cabergoline) is a dopamine agonist that inhibits prolactin secretion and shrinks the tumor.

GH stimulates the liver to produce IGF-1 (somatomedin C), which mediates most growth-promoting effects.

The posterior pituitary stores and releases ADH (vasopressin) and oxytocin, which are synthesized in the hypothalamus.

Diabetes insipidus (DI) results from ADH deficiency (central) or resistance (nephrogenic), causing inability to concentrate urine–leading to massive dilute polyuria.

In central DI, exogenous desmopressin concentrates the urine (>50% increase in osmolality).

Excess ADH causes water retention, diluting serum sodium (hyponatremia), while urine remains inappropriately concentrated.

Head trauma, neurosurgery, and tumors affecting the hypothalamus/pituitary stalk are common causes.

Desmopressin (DDAVP) is a synthetic ADH analog that replaces the deficient hormone.

Oxytocin stimulates uterine smooth muscle contraction during labor and postpartum hemostasis.

Lithium impairs aquaporin-2 channels in collecting ducts, causing ADH resistance.

Fluid restriction (800–1000 mL/day) is first-line for mild-moderate SIADH.

TSH is the most sensitive marker because small changes in thyroid hormone cause large reciprocal TSH changes (log-linear relationship).

Graves’ disease (autoimmune, TSH receptor antibodies) is the most common cause, especially in young women.

Graves’ ophthalmopathy is caused by TSH receptor antibodies attacking orbital tissues, causing inflammation and proptosis.

Hashimoto’s thyroiditis (chronic lymphocytic thyroiditis) is autoimmune destruction of the thyroid, with anti-TPO and anti-thyroglobulin antibodies.

Cold nodules don’t take up radioiodine and have ~5–15% malignancy risk, requiring FNAC evaluation.

PTU is preferred in thyroid storm because it blocks both thyroid hormone synthesis AND peripheral T4→T3 conversion.

Myxedema coma is life-threatening decompensated hypothyroidism with hypothermia, bradycardia, altered consciousness, and hypoglycemia.

Anti-thyroid peroxidase (anti-TPO) antibodies are highly specific for Hashimoto’s thyroiditis (>90% positive).

Papillary carcinoma accounts for ~80% of thyroid cancers.

Pretibial myxedema (dermopathy) is non-pitting edema over the shins, specific to Graves’ disease, caused by glycosaminoglycan deposition from TSH receptor antibodies.

Solitary parathyroid adenoma accounts for ~85% of primary hyperparathyroidism cases.

This classic mnemonic describes hypercalcemia from hyperparathyroidism: kidney stones, bone pain (bones), abdominal symptoms (groans), and neuropsychiatric changes (moans).

Inadvertent removal or devascularization of parathyroid glands during thyroid/parathyroid surgery is the most common cause.

Chvostek’s sign is facial muscle twitching upon tapping the facial nerve anterior to the ear.

Trousseau’s sign: inflating BP cuff above systolic for 3 minutes causes ischemia-induced carpopedal spasm (wrist flexion, thumb adduction) in hypocalcemia.

In primary hyperparathyroidism, autonomous PTH secretion causes hypercalcemia despite elevated PTH (inappropriate response).

IV calcium gluconate is the emergency treatment for symptomatic hypocalcemia (tetany, seizures, cardiac arrhythmias).

PTH increases calcium reabsorption in the distal tubule while causing phosphaturia by inhibiting phosphate reabsorption in the proximal tubule.

After parathyroidectomy for severe hyperparathyroidism, sudden PTH drop causes rapid calcium and phosphate uptake by bones (“hungry bones”), leading to profound hypocalcemia.

Diabetes is diagnosed with fasting glucose ≥126 mg/dL (7.0 mmol/L), random glucose ≥200 mg/dL with symptoms, 2-hour OGTT ≥200 mg/dL, or HbA1c ≥6.5%.

HbA1c measures glycated hemoglobin, reflecting average glucose over the RBC lifespan (~120 days), with the last 2–3 months weighted most heavily.

Type 1 DM results from T-cell mediated autoimmune destruction of pancreatic β-cells, causing absolute insulin deficiency.

DKA occurs in absolute insulin deficiency (Type 1 > Type 2), leading to hyperglycemia, ketosis, and metabolic acidosis.

DKA features hyperglycemia (usually >250 mg/dL), elevated ketones (β-hydroxybutyrate), and high anion gap metabolic acidosis (pH <7.3, bicarbonate <18).

Metformin is first-line due to efficacy, weight neutrality, low hypoglycemia risk, cardiovascular benefits, and low cost.

Metformin primarily reduces hepatic gluconeogenesis by activating AMPK.

Lactic acidosis is rare but potentially fatal, especially with renal impairment, liver disease, or contrast exposure.

Sulfonylureas (glibenclamide, gliclazide) bind SUR1 receptors on β-cells, closing K-ATP channels, causing depolarization and insulin secretion.

SGLT2 inhibitors block sodium-glucose cotransporter-2 in the proximal tubule, causing glucosuria and lowering blood glucose independently of insulin.

ADA recommends HbA1c <7% for most adults to reduce microvascular complications.

Hypoglycemia (<70 mg/dL) triggers adrenergic symptoms: tremor, sweating, palpitations, anxiety, hunger.

Somogyi effect is morning hyperglycemia caused by counter-regulatory hormone release (glucagon, cortisol, epinephrine) following nocturnal hypoglycemia.

Microalbuminuria (30–300 mg/day or urine albumin-to-creatinine ratio 30–300 mg/g) is the earliest detectable sign, indicating glomerular damage.

ACE inhibitors/ARBs reduce intraglomerular pressure by dilating efferent arterioles, slowing nephropathy progression.

Kimmelstiel-Wilson nodules are nodular glomerulosclerosis (eosinophilic PAS-positive deposits) pathognomonic of diabetic nephropathy.

Type 2 diabetes may be present for years before diagnosis, so screening begins immediately.

CKD stages: Stage 1 (≥90), Stage 2 (60–89), Stage 3 (30–59), Stage 4 (15–29), Stage 5 (<15 or dialysis).

Tighter BP control (<130/80) is recommended for diabetics with albuminuria to slow nephropathy progression.

SGLT2 inhibitors cause glucosuria, reducing sodium reabsorption and restoring tubuloglomerular feedback.

Renal ultrasound is non-invasive, avoids nephrotoxic contrast, and shows kidney size, echogenicity, and obstruction.

Iatrogenic Cushing’s from chronic corticosteroid therapy is the most common cause overall.

Cushing’s disease = pituitary ACTH adenoma (specific).

24-hour urinary free cortisol, late-night salivary cortisol, or overnight 1-mg dexamethasone suppression test are recommended screening tests.

Normally, 1 mg dexamethasone suppresses morning cortisol to <1.8 μg/dL by negative feedback.

Cushing’s syndrome causes central obesity, moon facies (rounded face), buffalo hump (dorsocervical fat), purple striae, and proximal muscle weakness.

Excess cortisol causes dermal collagen breakdown and skin thinning.

Small cell lung cancer is the most common cause of ectopic ACTH (~50%).

Transsphenoidal resection of the ACTH-secreting pituitary adenoma is first-line treatment for Cushing’s disease.

After bilateral adrenalectomy for Cushing’s disease, loss of cortisol feedback can cause aggressive expansion of the residual pituitary ACTH adenoma.

Addison’s disease is primary adrenal insufficiency–destruction of the adrenal cortex causing deficiency of cortisol, aldosterone, and androgens.

Autoimmune destruction (21-hydroxylase antibodies) accounts for ~80% of cases in developed countries.

Low cortisol removes negative feedback, increasing pituitary POMC (precursor to ACTH and MSH).

Aldosterone deficiency causes sodium wasting and potassium retention, leading to hyponatremia and hyperkalemia.

The ACTH (cosyntropin) stimulation test measures cortisol response to synthetic ACTH.

Addisonian crisis is life-threatening.

Both glucocorticoid (hydrocortisone 15–25 mg/day in divided doses) and mineralocorticoid (fludrocortisone 0.05–0.2 mg/day) replacement are needed.

Waterhouse-Friderichsen syndrome is bilateral adrenal hemorrhagic necrosis, classically associated with meningococcal sepsis (Neisseria meningitidis).

Chronic steroid use suppresses the HPA axis.

WHO classification: Underweight (<18.5), Normal (18.5–24.9), Overweight (25–29.9), Obesity Class I (30–34.9), Class II (35–39.9), Class III/Morbid (≥40).

Waist circumference measures abdominal/visceral fat, which correlates more strongly with cardiovascular and metabolic risk than subcutaneous fat.

Leptin is secreted by adipocytes proportional to fat mass and acts on the hypothalamus to reduce appetite and increase energy expenditure.

Ghrelin is secreted by gastric fundus cells and rises before meals, stimulating appetite via hypothalamic NPY/AgRP neurons.

Metabolic syndrome requires ≥3 of: central obesity, elevated triglycerides (≥150 mg/dL), low HDL, hypertension (≥130/85), and elevated fasting glucose (≥100 mg/dL).

Lifestyle intervention (reduced calorie diet, increased physical activity, behavioral therapy) is first-line for all patients.

Orlistat inhibits gastric and pancreatic lipases, reducing dietary fat absorption by 3 kg vs placebo).

Bariatric surgery indications: BMI ≥40, or BMI ≥35 with obesity-related comorbidities (diabetes, hypertension, sleep apnea), after failed lifestyle/medical management.

Roux-en-Y gastric bypass combines restriction (small pouch) with malabsorption (bypassed duodenum).

Minimal change disease (MCD) accounts for 80–90% of nephrotic syndrome in children aged 1–10 years.

Nephrotic syndrome is characterized by heavy proteinuria (>3.5 g/day or >40 mg/m²/hr in children), hypoalbuminemia (<2.5 g/dL), edema, and hyperlipidemia.

Prednisolone is the first-line treatment for minimal change disease, with >90% of children achieving remission.

Hypoalbuminemia reduces plasma oncotic pressure, causing fluid shift from intravascular to interstitial space, resulting in edema.

Renal biopsy is NOT required in typical childhood nephrotic syndrome (age 1–10 years, normal BP, no hematuria, normal complement, normal renal function) as most cases are minimal change disease.

Steroid-resistant nephrotic syndrome (SRNS) is defined as failure to achieve remission after 4 weeks of daily prednisolone at 60 mg/m²/day.

Infection (especially spontaneous bacterial peritonitis and pneumococcal infections) is the most serious and common complication due to urinary loss of immunoglobulins, complement factors, and properdin.

Frothy/foamy urine results from heavy proteinuria; proteins reduce surface tension of urine, creating bubbles.

LDL cholesterol is most significantly elevated in nephrotic syndrome due to increased hepatic synthesis (compensating for albumin loss) and decreased lipoprotein lipase activity.

Relapse is defined as urine protein ≥3+ (or ≥300 mg/dL, or protein:creatinine ratio ≥2) for 3 consecutive days after having achieved remission.

Frequently relapsing nephrotic syndrome (FRNS) is defined as ≥2 relapses within the first 6 months of initial response OR ≥4 relapses in any 12-month period.

Minimal change disease shows diffuse podocyte foot process effacement (fusion) on electron microscopy with no deposits.

Prerenal azotemia (due to dehydration from gastroenteritis, sepsis, or hypovolemia) is the most common cause of pediatric AKI, especially in developing countries.

In prerenal AKI, the kidneys avidly retain sodium to preserve volume, resulting in FeNa <1%.

The classic triad of HUS is microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and acute kidney injury.

Shiga toxin-producing E. coli O157:H7 causes >90% of typical (diarrhea-positive/D+) HUS in children.

Oliguria is defined as urine output <0.5 mL/kg/hr for >6 hours (KDIGO criteria).

Hyperkalemia is the most immediately life-threatening complication of AKI as it can cause fatal cardiac arrhythmias (peaked T waves → widened QRS → sine wave → cardiac arrest).

Peaked (tall, tented) T waves are the earliest ECG sign of hyperkalemia (K+ 5.5–6.5 mEq/L).

IV calcium gluconate is given first in severe hyperkalemia to stabilize the cardiac membrane–it doesn’t lower potassium but prevents arrhythmias within minutes.

Absolute indications for dialysis in AKI (remembered as AEIOU): Acidosis (refractory), Electrolyte abnormalities (refractory hyperkalemia), Ingestion (toxic), Overload (fluid, refractory), Uremia (encephalopathy, pericarditis).

In prerenal AKI, functioning tubules concentrate urine maximally to conserve water, resulting in specific gravity >1.020 and urine osmolality >500 mOsm/kg.

In prerenal AKI, increased passive reabsorption of urea (with water) occurs in hypovolemic states, while creatinine is not reabsorbed, leading to BUN:creatinine ratio >20:1.

ATN typically has three phases: initiation (hours-days), maintenance/oliguric phase (1–2 weeks), and recovery/polyuric phase (1–3 weeks).

CKD is defined as kidney damage (structural/functional abnormalities) or GFR <60 mL/min/1.73m² persisting for >3 months, regardless of cause.

CAKUT (including posterior urethral valves, vesicoureteral reflux, renal dysplasia/hypoplasia) accounts for 40–50% of pediatric CKD.

Secondary hyperparathyroidism is the primary driver of renal osteodystrophy.

Decreased erythropoietin (EPO) production by failing kidneys is the primary cause of CKD-associated anemia.

Children with CKD and proteinuria should have BP <50th percentile for age, sex, and height to slow CKD progression and reduce proteinuria.

ACE inhibitors (or ARBs) are first-line in CKD with proteinuria because they reduce intraglomerular pressure and proteinuria, slowing CKD progression (renoprotective effect).

Growth failure in CKD is primarily due to growth hormone resistance (not deficiency)–GH levels are normal or elevated, but IGF-1 bioactivity is reduced due to increased IGF-binding proteins.

CKD Stage 5 (kidney failure/ESKD) is defined as GFR <15 mL/min/1.73m² or requirement for dialysis/transplantation.

Kidney transplantation is the optimal RRT for children with ESKD, offering better growth, development, quality of life, and survival compared to dialysis.

In CKD, failing kidneys cannot excrete the daily acid load (dietary protein metabolism produces ~1 mEq/kg/day of H+) or regenerate bicarbonate adequately, leading to metabolic acidosis.

Familial (genetic) short stature is the most common cause of short stature, accounting for ~80% of cases.

Constitutional delay shows bone age delayed compared to chronological age (typically by 2–4 years), but appropriate for height age.

GH stimulation tests (using insulin, clonidine, arginine, or glucagon) are the gold standard for GHD diagnosis.

Craniopharyngioma is the most common tumor causing GHD and other pituitary hormone deficiencies in children.

Endocrine causes of short stature (hypothyroidism, GH deficiency, Cushing syndrome) typically present with short stature but relative obesity (increased weight-for-height).

Turner syndrome (45,XO) presents with short stature, webbed neck, shield chest, wide-spaced nipples, cubitus valgus, lymphedema, cardiac defects (coarctation), and streak ovaries causing primary amenorrhea (not precocious puberty).

Mid-parental height (MPH) estimates target height: For boys = (father’s height + mother’s height + 13)/2; For girls = (father’s height + mother’s height − 13)/2.

Normal growth velocity is >4 cm/year after age 4 years (roughly 5–6 cm/year prepubertally).

Thyroid function tests (TSH, free T4) are essential in ALL short stature evaluations because hypothyroidism is common, treatable, and easily missed.

Familial short stature shows proportionate short stature with normal growth velocity (parallel to but below normal curves), normal bone age, short parents, and no pathology.

Thyroid dysgenesis (agenesis, hypoplasia, ectopy) accounts for 80–85% of congenital hypothyroidism cases.

TSH is the most sensitive screening test for primary congenital hypothyroidism because it rises early even with borderline-low T4 (subclinical disease).

Treatment with levothyroxine should begin within 2 weeks of life (ideally by day 7–14) to prevent irreversible neurodevelopmental damage.

Hashimoto thyroiditis (chronic lymphocytic thyroiditis) is the most common cause of acquired hypothyroidism in children and adolescents in iodine-sufficient areas.

Hypothyroidism causes weight GAIN (not loss) due to decreased metabolism.

Graves disease (autoimmune, TSH receptor-stimulating antibodies) causes >95% of pediatric hyperthyroidism.

Exophthalmos (proptosis) is pathognomonic of Graves disease and doesn’t occur in other causes of hyperthyroidism.

Antithyroid drugs (carbimazole/methimazole or propylthiouracil) are first-line treatment in children with Graves disease, usually for 1–2 years to achieve remission.

Methimazole (or carbimazole, its prodrug) is preferred over propylthiouracil (PTU) in children due to PTU’s risk of severe hepatotoxicity (acute liver failure).

Neonatal thyrotoxicosis results from transplacental transfer of maternal TSH receptor-stimulating antibodies (TRAb/TSI) from mothers with Graves disease.

Type 1 DM results from autoimmune destruction of pancreatic beta cells, causing absolute insulin deficiency.

The classic triad is polyuria (osmotic diuresis from glycosuria), polydipsia (compensatory for fluid loss), and polyphagia (cellular starvation despite hyperglycemia).

DM is diagnosed by: fasting glucose ≥126 mg/dL, random glucose ≥200 mg/dL with symptoms, 2-hour OGTT ≥200 mg/dL, or HbA1c ≥6.5%.

DKA is the most common acute complication and may be the presenting feature in 25–40% of newly diagnosed T1DM in children.

DKA criteria: hyperglycemia (>200 mg/dL), acidosis (pH <7.3 or HCO3 <15 mmol/L), and ketonemia/ketonuria.

Fluid resuscitation is the FIRST priority in DKA to restore intravascular volume and improve tissue perfusion (children are typically 5–10% dehydrated).

Regular insulin continuous IV infusion at 0.05–0.1 units/kg/hour is standard DKA treatment.

Cerebral edema is a life-threatening complication of DKA treatment, associated with rapid fluid administration, rapid glucose reduction, and bicarbonate use.

The target HbA1c for most children/adolescents with T1DM is <7.0% (ISPAD/ADA guidelines), balancing glycemic control against hypoglycemia risk.

Dawn phenomenon is early morning (4–8 AM) hyperglycemia caused by overnight growth hormone and cortisol surges, which antagonize insulin.

The honeymoon phase is a period of temporary partial remission (weeks to months after diagnosis) where residual beta cell function reduces insulin requirements, sometimes to <0.5 units/kg/day.

Lipohypertrophy (fatty lumps) develops from repeated insulin injections at the same site due to insulin’s lipogenic effect.

Term neonate: 37–42 weeks gestation.

Calcium oxalate stones account for approximately 70–80% of all kidney stones.

Non-contrast CT (CT KUB) is the gold standard with >95% sensitivity and specificity for detecting all stone types.

Renal colic presents as severe, intermittent (colicky) flank pain radiating to the groin/genitalia as the stone moves down the ureter.

Uric acid stones are radiolucent (invisible on X-ray) because they lack calcium.

Gout causes hyperuricemia and acidic urine, promoting uric acid stone formation.

Staghorn calculi (large branching stones filling the renal pelvis) are typically struvite stones caused by urease-producing bacteria (Proteus).

Small stones (<5mm) have >90% spontaneous passage rate.

Acute cystitis (lower UTI) is the most common cause of dysuria in young women due to short urethra and proximity to vagina/rectum.

coli causes 80–85% of uncomplicated UTIs due to its uropathogenic properties and fecal colonization.

Nitrofurantoin is first-line for uncomplicated cystitis due to narrow spectrum, low resistance, and concentration in urine.

Painless gross hematuria in adults >50 is bladder cancer until proven otherwise.

Dysmorphic RBCs and RBC casts indicate glomerular damage (glomerulonephritis).

Cystoscopy is mandatory to visualize the bladder mucosa and rule out bladder cancer.

IgA nephropathy (Berger disease) classically presents with gross hematuria 1–2 days after upper respiratory infection (synpharyngitic hematuria).

Testicular torsion peaks in adolescents (12–18 years) during puberty when testicular volume increases rapidly.

Salvage rate is >90% if detorsion occurs within 6 hours.

Absent cremasteric reflex is highly sensitive for torsion (stroking inner thigh doesn’t elevate testis).

Surgical exploration with detorsion and bilateral orchidopexy (fixation of both testes) is definitive treatment.

Hydrocele is accumulation of serous fluid between the layers of tunica vaginalis surrounding the testis.

Transillumination is positive in hydrocele (light passes through fluid).

Congenital hydrocele results from a patent processus vaginalis allowing peritoneal fluid to accumulate around the testis.

Hydrocelectomy (Jaboulay’s or Lord’s procedure) is definitive treatment for symptomatic primary hydrocele.

Seminoma is the most common testicular germ cell tumor (40–50%), typically affecting men aged 25–45.

Testicular cancer classically presents as a painless, firm testicular mass.

Seminoma elevates beta-hCG (in 10–20%) and LDH but NEVER AFP.

Cryptorchidism (undescended testis) increases testicular cancer risk 4–10 times.

Radical inguinal orchiectomy (high ligation of spermatic cord) is the first step for diagnosis and treatment.

Chlamydia trachomatis and Neisseria gonorrhoeae cause epididymitis in sexually active young men.

Prehn’s sign is positive in epididymitis–pain improves with scrotal elevation (reduces venous congestion).

Empirical treatment covers gonorrhea (Ceftriaxone 500mg IM single dose) and chlamydia (Doxycycline 100mg BD for 10–14 days).

Papillary carcinoma accounts for 80–85% of thyroid cancers.

Thyroid ultrasound is the first-line investigation to assess nodule characteristics (size, echogenicity, vascularity, microcalcifications).

Microcalcifications (psammoma bodies) are highly suggestive of papillary carcinoma.

Cold nodules don’t take up radioiodine and have 10–15% malignancy risk, requiring FNAC.

FNAC is the gold standard for determining if a nodule is benign or malignant.

Peripheral neuropathy (60–70%) leads to loss of protective sensation, unnoticed injuries, and pressure-related ulcers.

Neuropathic ulcers occur at pressure points–plantar surface over metatarsal heads, heel, and bony prominences.

Staphylococcus aureus (including MRSA) is the most common pathogen.

Wagner classification grades diabetic foot ulcers (0–5) based on depth and presence of gangrene/infection.

Wound debridement (removing necrotic tissue) and offloading (pressure redistribution) are essential.

Fibroadenoma is the most common benign breast tumor in women aged 15–35.

Fibroadenoma is classically described as a “breast mouse”–smooth, rubbery, highly mobile, well-defined mass that slips under examining fingers.

Triple assessment combines: (1) Clinical examination, (2) Imaging (mammogram/ultrasound), and (3) Pathology (FNAC or core biopsy).

Ultrasound is preferred in young women (<35) due to dense breast tissue that limits mammographic sensitivity.

Invasive ductal carcinoma (IDC) accounts for 70–80% of breast cancers.

Peau d’orange (orange peel skin) indicates lymphatic obstruction from tumor invasion–a sign of locally advanced cancer.

Bloody/blood-stained nipple discharge requires urgent investigation (ductogram, cytology) to exclude intraductal papilloma or carcinoma.

The upper outer quadrant contains the most breast tissue (axillary tail) and accounts for approximately 50% of breast cancers.

Hypospadias is a congenital anomaly where the urethral meatus opens on the ventral (undersurface) of the penis, proximal to its normal position.

Glanular/distal hypospadias (meatus on glans or distal shaft) accounts for 70–80% of cases.

Surgical repair (urethroplasty) is ideally performed between 6–18 months–the penis is adequate size, anesthetic risk is acceptable, and psychological impact is minimized.

The foreskin provides tissue for urethroplasty during hypospadias repair.

Chordee (ventral penile curvature) is commonly associated with hypospadias due to abnormal urethral plate development.

Goals include: (1) meatus at normal position (tip of glans), (2) straight penis without chordee, (3) single urinary stream, and (4) normal appearance.

Fasting plasma glucose ≥126 mg/dL (7.0 mmol/L) on two occasions confirms diabetes.

HbA1c ≥6.5% (48 mmol/mol) confirms diabetes.

Metformin is first-line for type 2 diabetes–it reduces hepatic glucose production, improves insulin sensitivity, doesn’t cause hypoglycemia, and promotes modest weight loss.

GI side effects (nausea, diarrhea, abdominal discomfort) are most common with metformin.

Metformin is contraindicated in severe renal impairment (eGFR <30 mL/min) due to risk of lactic acidosis from drug accumulation.

HbA1c <7% is the target for most adults to reduce microvascular complications.

SGLT2 inhibitors (empagliflozin, dapagliflozin) have proven cardiovascular and renal benefits–reducing heart failure hospitalizations, cardiovascular death, and CKD progression.

Sulfonylureas stimulate insulin secretion regardless of glucose levels, causing hypoglycemia–especially in elderly, renal impairment, or missed meals.

HbA1c should be checked every 3–6 months depending on glycemic control.

BP target for diabetics is <130/80 mmHg to reduce micro- and macrovascular complications.

Diabetic retinopathy is screened by annual dilated fundus examination or retinal photography.

Urine albumin-to-creatinine ratio (UACR) detects microalbuminuria (earliest sign of diabetic nephropathy).

The 10g monofilament test assesses loss of protective sensation in feet (most vulnerable areas).

Weight loss (5–10% body weight) and regular physical activity (150 min/week) significantly improve insulin sensitivity and glycemic control.

Insulin is initiated when lifestyle + oral agents fail to achieve glycemic targets.

Comprehensive foot examination should be performed at least annually–more frequently in high-risk patients (neuropathy, deformity, prior ulcer/amputation).

Metformin should be temporarily stopped during acute illness causing dehydration, vomiting, or reduced intake–to prevent lactic acidosis from reduced renal clearance.

The “3 Ps” of DKA/severe hyperglycemia are polyuria (excessive urination), polydipsia (excessive thirst), and polyphagia/weight loss.

Statins are recommended for most diabetic patients >40 years for primary prevention of cardiovascular disease (ASCVD)–the leading cause of death in diabetics.

Low-dose aspirin (75–100 mg/day) is recommended for secondary prevention in diabetics with established cardiovascular disease.

Diabetics have increased infection risk and worse outcomes.

Cardiovascular disease (MI, stroke, peripheral arterial disease) accounts for 50–80% of deaths in type 2 diabetics.

ACE inhibitors/ARBs are preferred for diabetics with albuminuria/proteinuria–they reduce intraglomerular pressure, slow nephropathy progression, and provide CV protection.

Hypoglycemia is defined as blood glucose <70 mg/dL (<3.9 mmol/L).

The rule of 15: Give 15 grams of fast-acting carbohydrate (glucose tablets, juice, regular soda), wait 15 minutes, recheck glucose, and repeat if still <70 mg/dL.

Intensive lifestyle modification (weight loss 7%, 150 min/week exercise) reduces diabetes progression by 58%.

A primigravida is a woman pregnant for the first time (primi = first, gravida = pregnant).

At 20 weeks, the fundal height reaches the umbilicus.

Gravida refers to the total number of pregnancies regardless of outcome.

Leopold’s maneuvers are four abdominal palpation techniques to assess fetal lie, presentation, position, and engagement.

Normal fetal heart rate is 110–160 bpm.

The first antenatal visit should occur before 12 weeks for early risk assessment, dating, and screening.

Folic acid (400 mcg daily) prevents neural tube defects like spina bifida.

The anomaly scan (detailed ultrasound) is done at 18–22 weeks to detect structural abnormalities.

Women with normal BMI (18.5–24.9) should gain 11–16 kg.

Anti-D is given to Rh-negative mothers carrying Rh-positive fetuses to prevent isoimmunization.

BPP evaluates five parameters: fetal movement, tone, breathing, amniotic fluid, and NST.

A reactive NST shows ≥2 accelerations of ≥15 bpm for ≥15 seconds in 20 minutes, indicating fetal wellbeing.

BPP includes: breathing, movement, tone, amniotic fluid (AFI), and NST.

AFI < 5 cm indicates oligohydramnios.

Absent or reversed end-diastolic flow in the umbilical artery indicates severe placental insufficiency requiring urgent delivery.

Nuchal translucency is measured at 11–14 weeks as part of first-trimester screening for Down syndrome.

Amniocentesis provides fetal cells for karyotyping, giving definitive diagnosis.

CVS is done at 10–13 weeks for early diagnosis.

Elevated AFP suggests open neural tube defects (spina bifida, anencephaly).

Down syndrome shows low AFP, low estriol, high hCG, and high inhibin (quadruple screen).

Spontaneous abortion (miscarriage) is pregnancy loss before 20 weeks.

Ectopic pregnancy presents with amenorrhea, vaginal bleeding, and lower abdominal pain.

Placenta previa is placenta implanting over or near the internal cervical os.

Placental abruption causes painful vaginal bleeding with uterine tenderness and contractions.

Placenta accreta involves abnormal placental attachment to myometrium, preventing separation and causing massive hemorrhage.

Preterm labor occurs before 37 completed weeks.

Nifedipine (calcium channel blocker) inhibits uterine contractions.

Corticosteroids (betamethasone/dexamethasone) are given at 24–34 weeks for lung maturity if preterm delivery is anticipated.

Betamethasone crosses the placenta effectively and is the preferred steroid for fetal lung maturity.

Premature neonates lack surfactant, causing respiratory distress syndrome (RDS).

Preeclampsia is hypertension (≥140/90) after 20 weeks with proteinuria (≥300 mg/24h) or end-organ dysfunction.

Magnesium sulfate is first-line for preventing and treating eclamptic seizures.

Eclampsia is new-onset tonic-clonic seizures in a woman with preeclampsia not explained by other causes.

HELLP = Hemolysis, Elevated Liver enzymes, Low Platelets.

Definitive cure for preeclampsia is delivery.

GDM is diabetes first diagnosed in the second or third trimester without prior diabetes.

OGTT (75g or 100g) at 24–28 weeks is the standard screening test for GDM.

Macrosomia (>4000g) results from fetal hyperinsulinemia due to maternal hyperglycemia.

GDM screening is performed at 24–28 weeks when placental hormones maximally cause insulin resistance.

Neonatal hypoglycemia occurs because the neonate continues producing excess insulin after cord clamping removes maternal glucose supply.

TORCH = Toxoplasmosis, Other (syphilis, varicella, parvovirus), Rubella, CMV, Herpes simplex.

Rubella vaccination before pregnancy (MMR vaccine) prevents congenital rubella syndrome.

Antiretroviral therapy (ART) during pregnancy significantly reduces vertical HIV transmission to <1%.

Congenital rubella causes blueberry muffin rash (dermal erythropoiesis), along with cataracts and heart defects.

Intravenous penicillin is given during labor (intrapartum) to GBS-positive mothers to prevent neonatal sepsis, meningitis, and pneumonia.

First stage begins with regular contractions causing progressive cervical dilation until full dilation (10 cm).

Full dilation is 10 cm, marking the end of the first stage and beginning of the second stage of labor.

Second stage is from full dilation to delivery of the baby.

Third stage (placental delivery) normally completes within 30 minutes.

Oxytocin from the posterior pituitary causes uterine contractions.

Shoulder dystocia occurs when the anterior shoulder impacts behind the pubic symphysis after head delivery.

McRoberts maneuver (hyperflexion of maternal thighs) straightens the sacrum and increases pelvic diameter.

Cord prolapse (cord precedes presenting part) causes cord compression and fetal hypoxia.

Initial PPH management includes uterine massage to stimulate contractions and uterotonics (oxytocin).

Previous cesarean scar is the major risk factor for uterine rupture, especially during trial of labor.

Vertex (cephalic) presentation with occiput anterior is most common and favorable for vaginal delivery.

Engagement is the first movement where the biparietal diameter passes the pelvic inlet.

The fetal head rotates from transverse to occiput anterior, aligning the longest head diameter with the longest pelvic diameter.

Episiotomy is a surgical cut of the perineum to enlarge the vaginal opening during delivery.

Active management includes uterotonics (oxytocin), controlled cord traction, and uterine massage.

Primary PPH is blood loss ≥500 ml (vaginal) or ≥1000 ml (cesarean) within 24 hours of delivery.

Uterine atony (failure to contract) causes 70–80% of PPH.

Oxytocin is first-line for PPH prevention and treatment.

4 T’s = Tone (atony), Tissue (retained products), Trauma (tears), Thrombin (coagulopathy).

Bimanual compression (one hand vaginally, one abdominally) compresses the atonic uterus to stimulate contraction and reduce bleeding.

Puerperium is the 6-week period after delivery when the reproductive tract returns to the non-pregnant state.

Lochia is the vaginal discharge containing blood, mucus, and uterine tissue after delivery.

Lochia rubra (red, bloody) occurs days 1–3.

The uterus returns to pre-pregnancy size by 6 weeks postpartum.

Endometritis (uterine infection) is the most common cause of puerperal fever, especially after cesarean section.

Baby blues affect 50–80% of new mothers, typically peaking at days 3–5 postpartum and resolving by day 10.

Baby blues start around day 3, peak at days 3–5, and resolve by 10–14 days without treatment.

Postpartum depression can begin within days to 12 months postpartum, most commonly within the first 3 months.

Baby blues resolve in 10–14 days.

SSRIs (sertraline, paroxetine) combined with psychotherapy (CBT) are first-line for moderate PPD.

Postpartum psychosis usually presents within the first 2 weeks (often days 3–5) postpartum.

Postpartum psychosis features delusions, hallucinations, disorganized behavior, and rapid mood swings.

Postpartum psychosis is a psychiatric emergency requiring hospitalization for safety (risk of infanticide/suicide), stabilization, and treatment.

Postpartum psychosis has 25–50% recurrence risk in future pregnancies.

Untreated postpartum psychosis carries significant risk of infanticide and maternal suicide due to delusions and impaired judgment.

Renal biopsy is the gold standard for diagnosing glomerular diseases when nephrotic-range proteinuria is present, as it reveals histopathological patterns guiding specific treatment.

Both CKD-EPI and MDRD equations use serum creatinine, age, sex, and race to estimate GFR.

RBC casts form when red blood cells become entrapped in protein matrix within renal tubules, indicating glomerular bleeding – they are pathognomonic of glomerulonephritis.

Gadolinium-based contrast agents can cause nephrogenic systemic fibrosis (NSF) in patients with severe renal impairment (GFR <30 mL/min), leading to skin thickening and fibrosis of internal organs.

Muddy brown granular casts are pathognomonic of acute tubular necrosis (ATN), commonly caused by nephrotoxins (snake venom).

During sleep, the supine position allows fluid to redistribute to loose periorbital tissues due to gravity.

Elevated TSH with facial puffiness (myxedema) and dry skin suggests hypothyroidism.

This presentation suggests superior vena cava (SVC) syndrome – facial swelling, upper limb edema, distended neck veins, and plethora in a smoker raises suspicion for lung malignancy compressing SVC.