NEET MDS General Medicine Syllabus

Compare Crohn's disease and ulcerative colitis in distribution and depth of inflammation.

Crohn's: any part of GI tract (mouth to anus), skip lesions, transmural inflammation with granulomas. Ulcerative colitis: continuous involvement limited to colon/rectum, mucosal/submucosal inflammation only.

What is the most common cause of liver cirrhosis worldwide and in the West?

Worldwide: chronic viral hepatitis (B and C). In Western countries: alcoholic liver disease and metabolic dysfunction-associated steatotic liver disease (MASLD/NAFLD).

Name the components of the Child-Pugh score for cirrhosis severity.

Bilirubin, serum Albumin, INR (prothrombin time), Ascites, and Encephalopathy.

Which hepatitis viruses are transmitted enterically (fecal-oral) versus parenterally?

Fecal-oral: hepatitis A and E. Parenteral/blood-borne and sexual: hepatitis B, C, and D.

What serologic marker indicates acute hepatitis B, and which indicates immunity/recovery?

Acute infection: HBsAg positive with IgM anti-HBc. Immunity: anti-HBs positive (with anti-HBc indicating natural infection, or isolated anti-HBs indicating vaccination).

What is the difference between ischemic and hemorrhagic stroke, and which is more common?

Ischemic stroke (~85%) is caused by arterial occlusion/thrombosis or embolism; hemorrhagic stroke (~15%) results from rupture of a blood vessel (intracerebral or subarachnoid). Ischemic is far more common.

What is the time window and key contraindication consideration for IV thrombolysis (alteplase) in ischemic stroke?

IV tPA is given within 4.5 hours of symptom onset; hemorrhage must first be excluded by non-contrast CT, and active bleeding/recent surgery are contraindications.

Define status epilepticus.

A seizure lasting ≥5 minutes, or two or more seizures without full recovery of consciousness between them. It is a medical emergency.

What is the first-line drug for terminating an acute seizure / status epilepticus?

A benzodiazepine (IV lorazepam or diazepam, or IM midazolam), followed by a longer-acting antiepileptic such as levetiracetam, valproate, or phenytoin.

What are the cardinal motor features of Parkinson's disease?

Resting (pill-rolling) tremor, bradykinesia, rigidity (cogwheel), and postural instability. Caused by loss of dopaminergic neurons in the substantia nigra.

What is the most effective symptomatic drug for Parkinson's disease and why is it combined with carbidopa?

Levodopa is most effective; it is combined with carbidopa (a peripheral dopa-decarboxylase inhibitor) to reduce peripheral conversion, decrease side effects, and increase CNS delivery.

What pathological process underlies multiple sclerosis, and what are McDonald criteria based on?

Autoimmune demyelination of CNS white matter. Diagnosis uses McDonald criteria requiring dissemination in space and time (lesions in different CNS locations and at different times), supported by MRI and CSF oligoclonal bands.

Distinguish acute kidney injury (AKI) by its three categories.

Prerenal (decreased perfusion, e.g., hypovolemia), intrinsic/renal (tubular, glomerular, or interstitial damage e.g., ATN), and postrenal (urinary tract obstruction).

How do FENa and urine findings differentiate prerenal AKI from acute tubular necrosis?

Prerenal: FENa <1%, high urine osmolality, bland sediment. ATN: FENa >2%, low urine osmolality, muddy brown granular casts.

How is chronic kidney disease staged by GFR?

G1 ≥90, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 <15 mL/min/1.73 m2 (kidney failure), all with markers of kidney damage present for ≥3 months.

Differentiate nephritic from nephrotic syndrome.

Nephritic: hematuria, RBC casts, hypertension, mild-moderate proteinuria, oliguria (inflammatory glomerular disease). Nephrotic: heavy proteinuria (>3.5 g/day), hypoalbuminemia, edema, and hyperlipidemia.

What is the most common cause of nephrotic syndrome in children, and how does it respond to treatment?

Minimal change disease; it is highly responsive to corticosteroids.

What are the diagnostic glucose criteria for diabetes mellitus?

HbA1c ≥6.5%, fasting plasma glucose ≥126 mg/dL, 2-hour OGTT glucose ≥200 mg/dL, or random glucose ≥200 mg/dL with classic symptoms.

Contrast the pathophysiology of type 1 and type 2 diabetes mellitus.

Type 1: autoimmune destruction of pancreatic beta cells causing absolute insulin deficiency. Type 2: insulin resistance with relative insulin deficiency/secretory defect.

How do thyroid function tests differ in primary hypothyroidism versus primary hyperthyroidism?

Primary hypothyroidism: high TSH, low free T4. Primary hyperthyroidism: low (suppressed) TSH, high free T4/T3.

What is the most common cause of hyperthyroidism, and what antibody is associated?

Graves' disease, caused by TSH-receptor stimulating antibodies (TRAb/thyroid-stimulating immunoglobulins).

Compare Cushing's syndrome and Addison's disease.

Cushing's syndrome: cortisol excess (weight gain, moon face, striae, hypertension, hyperglycemia). Addison's disease: primary adrenal insufficiency with cortisol and aldosterone deficiency (fatigue, hypotension, hyperpigmentation, hyponatremia, hyperkalemia).

What hormone excess characterizes acromegaly, and what is its usual cause?

Excess growth hormone (and IGF-1), usually from a pituitary somatotroph adenoma; occurring before epiphyseal closure it causes gigantism.

How is anemia morphologically classified by MCV, with one example each?

Microcytic (MCV <80): iron deficiency. Normocytic (80-100): anemia of chronic disease, acute blood loss. Macrocytic (MCV >100): B12/folate deficiency (megaloblastic).

What is the most common cause of microcytic anemia worldwide, and its classic iron-study pattern?

Iron deficiency anemia: low serum ferritin, low serum iron, high TIBC/transferrin, low transferrin saturation.

Differentiate acute from chronic leukemia by blast count and onset.

Acute leukemia: rapid onset, ≥20% blasts in marrow, immature cells (AML, ALL). Chronic leukemia: insidious onset, accumulation of more mature cells (CML with Philadelphia chromosome, CLL).

What pathognomonic cell distinguishes Hodgkin from non-Hodgkin lymphoma?

The Reed-Sternberg cell, characteristic of Hodgkin lymphoma.

Contrast the coagulation defects in hemophilia A and von Willebrand disease.

Hemophilia A: X-linked deficiency of factor VIII, prolonged aPTT, deep tissue/joint bleeding. von Willebrand disease: deficient/defective vWF, prolonged bleeding time, mucocutaneous bleeding, autosomal inheritance (most common inherited bleeding disorder).

What laboratory abnormalities characterize disseminated intravascular coagulation (DIC)?

Prolonged PT and aPTT, low fibrinogen, low platelets, and elevated D-dimer/fibrin degradation products, with schistocytes on smear.

Which autoantibodies are most specific for rheumatoid arthritis, and what is the classic joint pattern?

Anti-CCP (anti-citrullinated peptide) antibodies are most specific (RF is sensitive but less specific). Symmetric polyarthritis of small joints (MCP, PIP) with morning stiffness >1 hour, sparing the DIP joints.

Which autoantibodies are highly specific for systemic lupus erythematosus?

Anti-double-stranded DNA (anti-dsDNA) and anti-Smith (anti-Sm) antibodies; ANA is sensitive (screening) but not specific.

What crystal causes gout, and how does it appear under polarized light?

Monosodium urate crystals: needle-shaped and negatively birefringent (yellow when parallel to the polarizer).

What antibody is associated with diffuse scleroderma versus limited (CREST) scleroderma?

Diffuse systemic sclerosis: anti-Scl-70 (anti-topoisomerase I). Limited/CREST: anti-centromere antibody. (CREST = Calcinosis, Raynaud's, Esophageal dysmotility, Sclerodactyly, Telangiectasia.)

What CD4 count defines AIDS, and which infections are AIDS-defining?

CD4 count <200 cells/mm3 (or an AIDS-defining illness). Examples: Pneumocystis jirovecii pneumonia, esophageal candidiasis, CMV retinitis, Kaposi sarcoma, cerebral toxoplasmosis.

What is the standard first-line drug regimen for new-onset drug-sensitive tuberculosis?

Intensive phase: Rifampin, Isoniazid, Pyrazinamide, Ethambutol (RIPE) for 2 months, then continuation phase of Rifampin + Isoniazid for 4 months (total 6 months).

Which Plasmodium species causes the most severe (cerebral) malaria, and what is the treatment of choice for severe malaria?

Plasmodium falciparum causes severe/cerebral malaria; IV artesunate is the treatment of choice for severe disease.

What are the warning signs of severe/complicated dengue fever?

Abdominal pain/tenderness, persistent vomiting, plasma leakage signs (pleural effusion, ascites), mucosal bleeding, lethargy/restlessness, hepatomegaly >2 cm, and a rising hematocrit with rapid platelet drop.

What is the classic peripheral smear and platelet finding in dengue fever?

Thrombocytopenia (low platelets), leukopenia, and hemoconcentration (raised hematocrit); NS1 antigen is positive early and IgM/IgG serology later.

What ECG territory and coronary artery correspond to an inferior wall MI?

Inferior MI shows changes in leads II, III, and aVF, usually due to occlusion of the right coronary artery (RCA).

What is the most common sustained arrhythmia, and what is its main thromboembolic complication?

Atrial fibrillation; its major complication is ischemic stroke from left atrial (appendage) thrombus embolization.