Cardiovascular and Respiratory Pathophysiology
Cardiovascular and respiratory diseases dominate every pathophysiology course. They account for the largest share of inpatient and primary care visits. Master mechanism, presentation, and key labs for each condition.
Core Cardiovascular Concepts
Understand how normal heart function breaks down across pump failure, valve dysfunction, and rhythm disorders. Atherosclerosis and myocardial infarction anchor most cardiovascular pathology. Follow each disease from mechanism to clinical presentation.
Core Respiratory Concepts
Obstructive diseases like asthma and COPD involve airway resistance. Restrictive diseases like ARDS limit lung expansion. Infectious diseases like pneumonia and TB change lung tissue directly. Know which category each disease fits.
High-Yield Cardiovascular Diseases
- Atherosclerosis: Lipid-rich plaques accumulate in arterial walls. Leads to stenosis, ischemia, and clot formation.
- Myocardial infarction: Cardiac muscle death from prolonged ischemia. Classic triad: chest pain, ECG changes, elevated troponin.
- Heart failure: Heart cannot pump adequate output. Left-sided failure causes pulmonary congestion. Right-sided failure causes peripheral edema and JVD.
- Hypertension: BP 130/80 or higher (Stage 1). Leads to left ventricular hypertrophy, CAD, stroke, and kidney disease. Usually asymptomatic until end-organ damage occurs.
- Atrial fibrillation: Disorganized atrial activity produces irregular rhythm. High stroke risk. Often requires anticoagulation.
- Valvular disease: Stenosis (obstruction) or regurgitation (backflow). Aortic stenosis produces systolic murmur and exertional syncope.
- Pulmonary embolism: Pulmonary artery obstruction from thrombus, usually from DVT. Presents with sudden dyspnea, pleuritic pain, tachycardia.
- Shock types: Hypovolemic, cardiogenic, obstructive, and distributive (septic, anaphylactic, neurogenic). Each has different preload, afterload, and cardiac output patterns.
High-Yield Respiratory Diseases
- Asthma: Reversible airway obstruction with bronchospasm, inflammation, and mucus. Presents with wheezing, cough, dyspnea.
- COPD: Chronic bronchitis and/or emphysema. Irreversible airflow obstruction. Smoking is the primary cause.
- Pneumonia: Lung infection with consolidation. CAP vs HAP distinction matters. Fever, productive cough, pleuritic chest pain are classic.
- ARDS: Noncardiogenic pulmonary edema with hypoxemia (PaO2/FiO2 ≤300) and bilateral infiltrates. Acute onset.
- Pneumothorax: Air in pleural space causing lung collapse. Tension pneumothorax is life-threatening with tracheal deviation.
- Cystic fibrosis: Autosomal recessive CFTR mutation. Thick secretions cause recurrent infections and pancreatic insufficiency.
- Tuberculosis: Mycobacterium tuberculosis infection. Ghon complex formation. Night sweats, weight loss, hemoptysis are classic.
- Pulmonary hypertension: Mean pulmonary artery pressure 25 mmHg or higher. Causes right heart strain and cor pulmonale.
| Term | Meaning |
|---|---|
| Atherosclerosis | Accumulation of lipid-rich plaques in arterial walls. Leads to stenosis, ischemia, and thromboembolism. |
| Myocardial infarction (MI) | Death of cardiac muscle due to prolonged ischemia. Classic triad: chest pain, ECG changes, elevated troponin. |
| Heart failure | Inability of the heart to pump adequate output. Left-sided causes pulmonary congestion; right-sided causes peripheral edema and JVD. |
| Hypertension | BP ≥130/80 (Stage 1). Leads to LVH, CAD, stroke, retinopathy, and CKD. Usually asymptomatic until end-organ damage. |
| Atrial fibrillation | Disorganized atrial activity producing an irregularly irregular rhythm. Risk of embolic stroke; often requires anticoagulation. |
| Valvular disease | Stenosis (obstruction) or regurgitation (backflow). Aortic stenosis produces a systolic murmur and syncope on exertion. |
| Pulmonary embolism | Obstruction of a pulmonary artery by a thrombus, usually from DVT. Presents with sudden dyspnea, pleuritic pain, tachycardia. |
| Shock (types) | Hypovolemic, cardiogenic, obstructive, distributive (septic, anaphylactic, neurogenic). Differ by preload, afterload, and cardiac output. |
| Asthma | Reversible airway obstruction with bronchospasm, inflammation, and mucus. Presents with wheezing, cough, dyspnea. |
| COPD | Chronic bronchitis and/or emphysema. Irreversible airflow obstruction. Smoking is the main cause. |
| Pneumonia | Lung infection with consolidation. CAP vs HAP. Classic presentation: fever, productive cough, pleuritic chest pain. |
| ARDS | Acute onset of noncardiogenic pulmonary edema with hypoxemia (PaO2/FiO2 ≤300) and bilateral infiltrates. |
| Pneumothorax | Air in the pleural space causing lung collapse. Tension pneumothorax is a life-threatening variant with tracheal deviation. |
| Cystic fibrosis | Autosomal recessive CFTR mutation. Thick secretions cause recurrent pulmonary infections, pancreatic insufficiency, infertility. |
| Tuberculosis | Mycobacterium tuberculosis infection. Ghon complex; night sweats, weight loss, hemoptysis. Airborne precautions. |
| Pulmonary hypertension | Mean pulmonary artery pressure ≥25 mmHg. Causes right heart strain and eventual cor pulmonale. |
Endocrine, Renal, and GI Pathophysiology
These three systems account for another large chunk of pathophysiology exam content. Focus on mechanism, hallmark labs, and common complications for each disease.
Endocrine Disease Framework
Diabetes is the most common endocrine disorder tested. Know the distinction between Type 1 (autoimmune, absolute insulin deficiency) and Type 2 (insulin resistance, relative deficiency). Thyroid disease affects metabolism and affects nearly every system. Adrenal disorders cause electrolyte chaos.
Renal Disease Framework
Renal pathology follows three categories: prerenal (blood flow problem), intrinsic (kidney tissue damage), and postrenal (obstruction). Glomerular diseases present as either nephrotic (proteinuria-dominant) or nephritic (hematuria-dominant).
GI Disease Framework
GI diseases span infection, inflammation, mechanical obstruction, and malignancy. Organize by anatomical location (esophagus, stomach, small bowel, colon) and pathologic process (reflux, ulceration, inflammation).
High-Yield Endocrine Diseases
- Type 1 diabetes: Autoimmune beta cell destruction. Requires insulin. DKA is a classic complication.
- Type 2 diabetes: Insulin resistance with relative insulin deficiency. Associated with obesity. HHS is a severe complication.
- DKA: Hyperglycemia, ketosis, metabolic acidosis. Kussmaul respirations, fruity breath, dehydration are hallmarks.
- Hyperthyroidism: Elevated thyroid hormone with suppressed TSH. Graves disease is most common. Weight loss, tachycardia, heat intolerance.
- Hypothyroidism: Low thyroid hormone with elevated TSH. Hashimoto is most common. Fatigue, weight gain, cold intolerance, bradycardia.
- Cushing syndrome: Excess cortisol. Moon face, buffalo hump, striae, central obesity, hyperglycemia. Often iatrogenic from steroids.
- Addison disease: Primary adrenal insufficiency. Hyperpigmentation, hypotension, hyponatremia, hyperkalemia.
High-Yield Renal Diseases
- Acute kidney injury: Rapid renal function loss. Prerenal (hypoperfusion), intrinsic (ATN), or postrenal (obstruction) categories.
- Chronic kidney disease: Progressive GFR loss over 3+ months. Leads to anemia, bone disease, volume overload, acidosis, hyperkalemia.
- Nephrotic syndrome: Massive proteinuria (>3.5 g/day), hypoalbuminemia, edema, hyperlipidemia.
- Nephritic syndrome: Hematuria, RBC casts, mild proteinuria, hypertension, azotemia. Post-streptococcal glomerulonephritis is classic.
High-Yield GI Diseases
- GERD: Retrograde gastric content flow. Heartburn, regurgitation. Chronic disease may cause Barrett esophagus.
- Peptic ulcer disease: Mucosal break in stomach or duodenum. H. pylori and NSAIDs are leading causes. Risk of bleeding and perforation.
- Cirrhosis: End-stage liver fibrosis. Portal hypertension, varices, ascites, hepatic encephalopathy, spontaneous bacterial peritonitis.
- Pancreatitis: Pancreas inflammation. Acute causes: gallstones, alcohol. Elevated lipase and amylase.
- Inflammatory bowel disease: Crohn disease (transmural, skip lesions) vs ulcerative colitis (continuous mucosal, colon only).
| Term | Meaning |
|---|---|
| Type 1 diabetes | Autoimmune destruction of pancreatic beta cells leading to insulin deficiency. Requires insulin. DKA is a classic complication. |
| Type 2 diabetes | Insulin resistance with relative insulin deficiency. Associated with obesity. HHS is a severe complication. |
| DKA | Hyperglycemia, ketosis, metabolic acidosis. Presents with Kussmaul respirations, fruity breath, dehydration. |
| Hyperthyroidism | Elevated thyroid hormone with suppressed TSH. Graves disease is the most common cause. Weight loss, tachycardia, heat intolerance. |
| Hypothyroidism | Low thyroid hormone with elevated TSH. Hashimoto is most common. Fatigue, weight gain, cold intolerance, bradycardia. |
| Cushing syndrome | Excess cortisol. Moon face, buffalo hump, striae, central obesity, hyperglycemia. Often iatrogenic from steroids. |
| Addison disease | Primary adrenal insufficiency. Hyperpigmentation, hypotension, hyponatremia, hyperkalemia. |
| Acute kidney injury (AKI) | Rapid loss of renal function. Classified as prerenal (hypoperfusion), intrinsic (ATN), or postrenal (obstruction). |
| Chronic kidney disease | Progressive loss of GFR over ≥3 months. Leads to anemia, bone disease, volume overload, acidosis, hyperkalemia. |
| Nephrotic syndrome | Massive proteinuria (>3.5 g/day), hypoalbuminemia, edema, hyperlipidemia. |
| Nephritic syndrome | Hematuria, RBC casts, mild proteinuria, HTN, azotemia. Post-streptococcal glomerulonephritis is classic. |
| GERD | Retrograde flow of gastric contents. Heartburn, regurgitation. Chronic disease may cause Barrett esophagus. |
| Peptic ulcer disease | Mucosal break in stomach or duodenum. H. pylori and NSAIDs are leading causes. Risk of bleeding and perforation. |
| Cirrhosis | End-stage liver fibrosis. Complications: portal hypertension, varices, ascites, hepatic encephalopathy, SBP. |
| Pancreatitis | Inflammation of the pancreas. Acute causes: gallstones, alcohol. Elevated lipase and amylase. |
| Inflammatory bowel disease | Crohn disease (transmural, skip lesions, anywhere GI) vs ulcerative colitis (continuous mucosal, colon only). |
Neurologic, Hematologic, and Immune Pathophysiology
The remaining systems round out a full pathophysiology course. Focus on the most commonly tested diseases: stroke, seizures, anemias, and autoimmune conditions.
Neurologic Disease Organization
Stroke is the most time-sensitive neurologic emergency. Know ischemic vs hemorrhagic, because treatments differ dramatically. Seizures are sudden abnormal neuronal firing. Neurodegenerative diseases involve progressive cell loss. Neuromuscular disorders disrupt signal transmission.
Hematologic and Immune Disease Organization
Anemias result from blood loss, decreased production, or increased destruction. Malignancies include leukemias and lymphomas. Autoimmune diseases involve immune self-attack. Immunodeficiency (HIV/AIDS) removes immune protection.
High-Yield Neurologic Diseases
- Ischemic stroke: Cerebral artery obstruction causing infarction. Sudden focal neurologic deficit. tPA effective within 3 to 4.5 hours if eligible.
- Hemorrhagic stroke: Brain bleeding in parenchyma or subarachnoid space. Severe headache, vomiting, decreased consciousness.
- Seizure: Abnormal synchronous neuronal firing. Focal (partial) vs generalized (tonic-clonic, absence). Status epilepticus is a medical emergency.
- Multiple sclerosis: Autoimmune CNS demyelination. Relapsing-remitting course. Symptoms vary by lesion location.
- Parkinson disease: Dopaminergic neuron loss in substantia nigra. TRAP mnemonic: tremor, rigidity, akinesia, postural instability.
- Alzheimer disease: Progressive neurodegeneration with amyloid plaques and neurofibrillary tangles. Most common dementia cause.
- Myasthenia gravis: Autoantibodies against acetylcholine receptors. Fluctuating muscle weakness worse with activity, better with rest.
High-Yield Hematologic Diseases
- Iron deficiency anemia: Microcytic, hypochromic anemia. Low ferritin, high TIBC. Causes: chronic bleeding, poor intake, malabsorption.
- Vitamin B12 deficiency: Macrocytic anemia with neurologic symptoms. Pernicious anemia involves autoimmune parietal cell destruction.
- Sickle cell disease: Autosomal recessive HbS mutation. Vaso-occlusive crises, aplastic crisis, autosplenectomy.
- Leukemia: Malignancy of WBC precursors. Acute (ALL, AML) or chronic (CLL, CML). Pancytopenia and circulating blasts.
- Lymphoma: Lymphocyte malignancy. Hodgkin (Reed-Sternberg cells) and non-Hodgkin types.
High-Yield Immune Diseases
- Systemic lupus erythematosus: Autoimmune multisystem disease. ANA and anti-dsDNA positive. Malar rash, arthritis, nephritis.
- Rheumatoid arthritis: Autoimmune polyarthritis with symmetric involvement. Morning stiffness over 1 hour. RF and anti-CCP antibodies.
- HIV/AIDS: Retroviral CD4 cell infection. Progressive immunodeficiency. AIDS defined by CD4 <200 or opportunistic infection.
- Anaphylaxis: IgE-mediated Type I hypersensitivity. Airway edema, hypotension, urticaria. Treat with epinephrine.
| Term | Meaning |
|---|---|
| Ischemic stroke | Obstruction of cerebral artery causing infarction. Sudden focal neurologic deficit. tPA within 3-4.5 hours if eligible. |
| Hemorrhagic stroke | Bleeding into brain parenchyma or subarachnoid space. Severe headache, vomiting, decreased consciousness. |
| Seizure | Abnormal synchronous neuronal firing. Focal (partial) vs generalized (tonic-clonic, absence). Status epilepticus is a medical emergency. |
| Multiple sclerosis | Autoimmune demyelination of CNS. Relapsing-remitting course. Symptoms vary by lesion location. |
| Parkinson disease | Loss of dopaminergic neurons in substantia nigra. TRAP: tremor, rigidity, akinesia, postural instability. |
| Alzheimer disease | Progressive neurodegeneration with amyloid plaques and neurofibrillary tangles. Most common cause of dementia. |
| Myasthenia gravis | Autoantibodies against acetylcholine receptors. Fluctuating muscle weakness worse with activity, better with rest. |
| Iron deficiency anemia | Microcytic, hypochromic anemia. Low ferritin, high TIBC. Causes: chronic bleeding, poor intake, malabsorption. |
| Vitamin B12 deficiency | Macrocytic anemia with neurologic symptoms. Pernicious anemia is autoimmune destruction of parietal cells. |
| Sickle cell disease | Autosomal recessive HbS mutation. Vaso-occlusive crises, aplastic crisis, autosplenectomy. |
| Leukemia | Malignancy of WBC precursors. Acute (ALL, AML) or chronic (CLL, CML). Presents with pancytopenia and blasts. |
| Lymphoma | Malignancy of lymphocytes. Hodgkin (Reed-Sternberg cells) and non-Hodgkin types. |
| Systemic lupus erythematosus | Autoimmune disease with multisystem involvement. ANA, anti-dsDNA positive. Malar rash, arthritis, nephritis. |
| Rheumatoid arthritis | Autoimmune polyarthritis with symmetric joint involvement, morning stiffness >1 hour, RF and anti-CCP antibodies. |
| HIV/AIDS | Retroviral infection of CD4 cells. Progressive immunodeficiency. AIDS defined by CD4 <200 or opportunistic infection. |
| Anaphylaxis | IgE-mediated type I hypersensitivity. Airway edema, hypotension, urticaria. Treat with epinephrine. |
How to Study pathophysiology Effectively
Mastering pathophysiology requires the right study approach, not just more hours. Research in cognitive science consistently shows that three techniques produce the best learning outcomes: active recall (testing yourself), spaced repetition (reviewing at scientifically-optimized intervals), and interleaving (mixing related topics). FluentFlash is built around all three.
When you study pathophysiology with our FSRS algorithm, every term is scheduled at exactly the moment before forgetting. This maximizes retention while minimizing study time. Most students see significant improvement within 2 to 3 weeks of consistent daily practice.
Why Passive Review Fails
The most common mistake is relying on passive methods. Re-reading notes, highlighting textbook passages, or watching lectures feels productive. Studies show these methods produce only 10 to 20% of the retention that active recall achieves. Flashcards force your brain to retrieve information, which strengthens memory pathways far more than recognition alone.
Building Your Study System
- Generate flashcards using FluentFlash AI or create them manually from course notes
- Study 15 to 20 new cards daily, plus scheduled reviews
- Use multiple study modes (flip, multiple choice, written) to strengthen recall
- Track your progress and identify weak topics for focused review
- Review consistently. Daily practice beats marathon sessions every time.
- 1
Generate flashcards using FluentFlash AI or create them manually from your notes
- 2
Study 15-20 new cards per day, plus scheduled reviews
- 3
Use multiple study modes (flip, multiple choice, written) to strengthen recall
- 4
Track your progress and identify weak topics for focused review
- 5
Review consistently, daily practice beats marathon sessions
Why Flashcards Work Better Than Other Study Methods for pathophysiology
Flashcards aren't just for vocabulary. They're one of the most research-backed study tools for any subject, including pathophysiology. Memory works through retrieval, not exposure. When you read a textbook passage, your brain stores information in short-term memory. Without retrieval practice, it fades within hours. Flashcards force retrieval, which transfers information from short-term to long-term memory.
The Testing Effect
The testing effect is documented in hundreds of peer-reviewed studies. Students who study with flashcards consistently outperform those who re-read by 30 to 60% on delayed tests. This isn't because flashcards contain more information. It's because retrieval strengthens neural pathways in ways passive exposure cannot. Every successful recall makes that concept easier to retrieve next time.
FSRS Optimization
FluentFlash amplifies this effect with the FSRS algorithm, a modern spaced repetition system that schedules reviews at mathematically-optimal intervals based on your performance. Cards you find easy get pushed further into the future. Cards you struggle with come back sooner. Over time, this builds remarkable retention with minimal time investment.
Students using FSRS-based systems typically retain 85 to 95% of material after 30 days. Compare this to roughly 20% retention from passive review alone. The difference is dramatic and reproducible across thousands of learners.