Master Internal Medicine
for USMLE Step 2 CK
Access 50+ high-yield questions tailored for the 2026 syllabus. Includes AI-powered explanations and performance tracking.
Core Concepts
Internal Medicine on USMLE Step 2 CK emphasizes a structured approach to common adult diseases, focusing on differential diagnosis, initial workup, and first-line management. Key principles include recognizing life-threatening conditions, understanding pathophysiology, and applying evidence-based medicine. Many questions test the ability to interpret lab results, imaging, and patient history to arrive at the most likely diagnosis and appropriate intervention. Always consider patient comorbidities and drug interactions.
Clinical Presentation
- Cardiology: Chest pain (anginal vs. pleuritic vs. positional), dyspnea (exertional, orthopnea, PND), palpitations, syncope, peripheral edema.
- Pulmonology: Cough (acute vs. chronic, productive vs. dry), dyspnea (acute vs. chronic, inspiratory vs. expiratory), hemoptysis, wheezing, pleuritic chest pain.
- Gastroenterology: Abdominal pain (location, character, radiation), nausea/vomiting, diarrhea/constipation, GI bleeding (hematemesis, melena, hematochezia), jaundice, dysphagia.
- Nephrology: Edema, changes in urine output, flank pain, hematuria, polyuria/polydipsia, symptoms of uremia (fatigue, pruritus, altered mental status).
- Endocrinology: Weight changes (gain/loss), polyuria/polydipsia, heat/cold intolerance, fatigue, changes in skin/hair, mood disturbances.
- Rheumatology: Joint pain/swelling (monoarticular vs. polyarticular, inflammatory vs. mechanical), morning stiffness, rash, oral ulcers, photosensitivity, Raynaud's phenomenon.
- Hematology/Oncology: Fatigue, pallor, easy bruising/bleeding, recurrent infections, unexplained weight loss, night sweats, lymphadenopathy.
- Infectious Disease: Fever, chills, myalgias, localized pain, rash, lymphadenopathy.
Diagnosis (Gold Standard)
Often involves a combination of clinical picture, labs, and imaging.
- MI: ECG changes (ST elevation/depression, T-wave inversion) + cardiac troponins.
- Heart Failure: Echocardiogram (EF, ventricular function).
- Pulmonary Embolism (PE): CT Pulmonary Angiography (CT-PA).
- COPD/Asthma: Spirometry (FEV1/FVC ratio).
- Peptic Ulcer Disease (PUD): Upper Endoscopy.
- Acute Pancreatitis: Lipase >3x ULN + characteristic abdominal pain.
- IBD (Crohn's/UC): Colonoscopy with biopsy.
- Chronic Kidney Disease (CKD): eGFR <60 for >3 months + albuminuria.
- Diabetes Mellitus: HbA1c ≥6.5% OR FBG ≥126 mg/dL OR 2hr OGTT ≥200 mg/dL OR random BG ≥200 mg/dL with symptoms.
- Hypothyroidism: Elevated TSH, low Free T4.
- Gout: Synovial fluid analysis showing negatively birefringent needle-shaped crystals.
- Lupus (SLE): Clinical criteria + positive ANA (highly sensitive).
- Sepsis: Suspected infection + new organ dysfunction (SOFA score).
Management (First Line)
- MI (STEMI): Aspirin, P2Y12 inhibitor, nitrates, statin, O2, morphine + prompt reperfusion (PCI within 90-120 min or fibrinolytics).
- Heart Failure (HFrEF): ACEi/ARB, beta-blocker, aldosterone antagonist, SGLT2 inhibitor. Loop diuretics for symptom relief.
- Hypertension: Lifestyle modifications. First-line agents: Thiazide diuretics, ACEi/ARB, CCB.
- PE: Anticoagulation (heparin products, then oral DOACs). Thrombolysis for massive PE with hemodynamic instability.
- COPD Exacerbation: SABA, systemic corticosteroids, antibiotics if signs of bacterial infection.
- Asthma Exacerbation: SABA, systemic corticosteroids.
- PUD: PPI. H. pylori eradication (PPI + 2-3 antibiotics) if present.
- Acute Pancreatitis: Aggressive IV fluids, pain control, NPO.
- Diabetic Ketoacidosis (DKA): IV fluids, insulin drip, potassium replacement.
- Hypothyroidism: Levothyroxine.
- Gout Flare: NSAIDs (e.g., indomethacin), colchicine, or oral corticosteroids.
- Septic Shock: IV fluid resuscitation (30ml/kg crystalloids), broad-spectrum antibiotics (within 1 hour), vasopressors (norepinephrine) if hypotension persists.
- Community-Acquired Pneumonia (CAP): Macrolide or doxycycline (outpatient); ceftriaxone + azithromycin/doxycycline or fluoroquinolone (inpatient).
Exam Red Flags
- Acute Chest Pain + ST Elevation/New LBBB: STEMI - activate cath lab!
- Acute Dyspnea + Hypotension + Tachycardia: Consider PE, cardiac tamponade, tension pneumothorax.
- Sudden, Severe Headache + Stiff Neck: Meningitis or subarachnoid hemorrhage.
- Abdominal Pain + Peritoneal Signs + Hypotension: Surgical emergency (e.g., perforation, ruptured AAA, mesenteric ischemia).
- GI Bleed + Hemodynamic Instability: Requires immediate fluid resuscitation, blood products, and emergent endoscopy/intervention.
- Altered Mental Status + Fever + Hypotension: Sepsis/Septic Shock - STAT fluids and broad-spectrum antibiotics.
- Acute Unilateral Vision Loss + Pain on Eye Movement: Optic neuritis (often MS).
- Unilateral Weakness/Numbness + Facial Droop + Aphasia: Stroke - activate stroke protocol!
- Diabetic + Altered Mental Status + Kussmaul Respirations: DKA.
Sample Practice Questions
A 70-year-old male with a known history of chronic obstructive pulmonary disease (COPD) presents with a 2-day history of worsening dyspnea, increased cough, and a change in sputum color from clear to yellow. He uses home oxygen at 2 L/min, but his oxygen saturation is currently 88% on room air. On examination, he is tachypneic with prolonged expiration and diffuse wheezing. Which of the following is the most appropriate initial pharmacologic treatment?
A 68-year-old male with a 20-year history of COPD presents to the emergency department with a 2-day history of increased shortness of breath, a productive cough with purulent sputum, and subjective fever. He reports using his albuterol inhaler more frequently than usual without much relief. His vital signs are: Temperature 100.8°F (38.2°C), HR 95 bpm, RR 28 breaths/min, BP 130/75 mmHg, and SpO2 90% on room air. Physical examination reveals diffuse inspiratory and expiratory wheezes, prolonged expiratory phase, and decreased breath sounds bilaterally. A chest X-ray shows hyperinflated lungs with flattened diaphragms, but no new infiltrates. What is the most appropriate initial management for this patient?
A 45-year-old male with a history of chronic alcohol abuse presents to the emergency department with acute onset hematemesis and melena. On arrival, his blood pressure is 90/60 mmHg, heart rate 110 bpm, and he appears pale and diaphoretic. His initial hemoglobin is 8.5 g/dL. Which of the following is the most appropriate immediate next step in management?
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