Respiratory
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  • Obstructive: FEV1/FVC < 80%, TLC↑
    • Asthma: allergy (episodic attacks) causes wheeze, cough (esp at night) and SOB, dx with methacholine test, tx with albuterol (acute) and advair (maintenance).
    • COPD (dyspnea): chronic bronchitis (cough+sputum) and emphysema (barrel chest) due to smoking, exertional dyspnea, morning headache, hypoxia.
      • Chronic bronchitis: long time (3 mo/yr, 2 yr) cough with mucus due to inflammation of bronchi.
      • Emphysema: barrel chest with fast, shallow breathing, due to alveolar septa destruction, CXR shows loss of lung tissue (black/air), tx with lung vol reduction surgery.
    • Bronchiectasis: cough, muco-purulent sputum, hemoptysis, recurrent sinusitis, CT shows dilated peripheral airways.
      • CF: Recurrent sinusitis, thick sputum, pancreatic insufficiency (steatorrhea), meconium ileus, infertility, dx by sweat chloride↑, CFTR mutation.
      • PCD (Kartagener's): immotile cilia causing recurrent ear/sinus infections, situs inversus, infertility, bronchiectasis, dx by reduced nasal NO and brush biopsy showing immotile cilia.
  • Restrictive: FEV1/FVC > 80%, TLC↓
    • ILD: SOB, non-productive cough due to damage to interstitium (not inside airspace): sarcoidosis, hypersensitivity pneumonitis, pneumoconiosis, IPF, organizing DAD.
    • BOOP: pneumonia-like (acute, cough, fever, SOB) with wt loss, but no sputum and doesn't respond to antibiotics.
    • Muscle weakness
  • ILD: SOB, non-productive cough due to damage to interstitium (not inside airspace): sarcoidosis, hypersensitivity pneumonitis, pneumoconiosis, IPF, organizing DAD.
    • Sarcoidosis: SOB, hilar adenopathy, skin (face plaques, ankle erythema), arthritis, diffuse opacity on CXR, non-caseating granulomas.
    • Hypersensitivity pneumonitis: exposure to farm/organic dust causes cough, SOB, fatigue, CXR shows bilateral diffuse (nodular) infiltrates, biopsy shows loosely formed granulomas and thick alveoli septa.
    • IPF: Cough, exertional dyspnea, CXR shows patchy subpleural infiltrates, biopsy shows patches of fibrosis and normal lung (temporal heterogeneity).
    • AIP: Fever, cough, worsening dyspnea over 1-2 weeks, will progress to the inability to breath, CXR shows bilateral diffuse opacities, lung biopsy shows organizing DAD, tx with mechanical ventilation.
    • Pneumoconiosis: Restrictive lung disease caused by breathing in various inorganic dusts (asbestos, silica, coal, metals, cotton).
      • Asbestosis: insidious onset of dyspnea with exertion due to hx of asbestos exposure, CXR shows peripheral opacities, pleural plaques, lavage shows asbestos fibers.
      • Silicosis: sand blaster comes in with cough, SOB, chest xray shows nodules located centrally, biopsy shows fibrotic nodules surrounded by macrophages containing silica.
  • Alveolar lung disease: Infiltration of the alveolar air spaces, fluffy texture to CXR with air bronchograms.
    • ARDS: shock/sepsis triggers rapid decline in pulmonary function: PaO2↓, O2 sat↓, SOB, tachypnea, CXR shows bilateral diffuse fluffy opacities with air bronchograms, tx with mechanical ventilation.
    • IRDS: Premature babies have respiratory failure (labored breathing, hypoxia, tachypnea) due to insufficient surfactant in lungs, tx with mechical ventilation, O2, and exogenous surfactant.
    • Goodpasture's syndrome: Lung (SOB, hemoptysis, diffuse opacities), Renal (hematuria) and fatigue due to anti-GBM - renal biopsy shows crescents and IgG deposition.
    • Lupus: buttefly rash, photosensitivity, fatigue, joint pain (hands) and a whole bunch of organ systems involved - dx by ANA and anti-dsDNA antibodies.
    • GPA (Wegener's): ENT (sinusitis, crusting), pulm and renal (hemoptysis, hematuria), vasculitis (purpura), due to ANCA, perivascular granulomas, glomerular crescents without immune deposits.
    • Pneumonia
    • Pulmonary edema
  • Infections
    • Pneumonia
      • Pneumococcal pneumonia: fever, cough, chest pain, rusty sputum, increased white count, lung opacities, dx with sputum gram stain, urine antigen, blood culture, tx with azithromycin (normal) or levofloxacin (sick).
      • Aspiration pneumonia: pneumonia (fever, cough, chills) with purulent, smelly sputum, xray shows abscess, hx of anesthesia, EtOH, seizures, tx with Clindamycin for anaerobes.
      • Mycoplasma pneumonia: mild pneumonia (fever, cough, chills), pharyngitis, dx with serology (IgM, cold agglutinins) and PCR.
    • TB: chest pain, cough, nightsweats, hemoptysis, foreign/abroad/prison hx, apical lung opacities with cavitation.
      • Primary TB: Ghon complex: interlobar granuloma (Ghon focus) + hilar/mediastinal adenopathy, mild symptoms (low-grade fever, chest pain).
      • Reactivation TB: classical presentation of fever, cough, night sweats, chest pain, hemoptysis, apical lung opacities with cavitation.
      • Miliary TB: Hematogenous spread of TB, granulomas in many organs, CXR shows lung dotted with seed-like opacities.
    • Aspergilla
      • Simple aspergilloma: mild cough, fungus ball confined to the lung, shows up on CXR.
      • Pulmonary aspergillosis: Fever, cough, pleuritic chest pain, hemoptysis, hx of immunocompromise, CXR shows lung consolidation with cavitation, dx by serology and culture, tx with voriconazole.
      • ABPA: asthmatics allergic to aspergillus, eosinophilia, IgE↑, dx by skin test to aspergillus.
    • Epiglottitis: fever, sore throat, dysphagia, drooling, insp stridor, tripod, caused by H flu, dx w swollen epiglottis, thick aryepiglottic fold (thumb sign on xray).
    • Croup: insp stridor, seal bark cough, hoarse, due to paraflu, tx w glucocorticoids, epinephrine.
    • Bronchiolitis: kids, winter, fever, cough, wheezing, resp distress, caused by RSV.
    • PCP: Fever, cough, SOB in immunocompromised, diffuse lung opacities, dx by microscopy (staining, immunofluorescence) of respiratory samples (induced sputum, lavage, biopsy).
    • Other viral: CMV (owl's eyes), Herpes (molded nuclei)
  • Fever
    • Pneumonia
    • TB: chest pain, cough, nightsweats, hemoptysis, foreign/abroad/prison hx, apical lung opacities with cavitation.
    • BOOP: pneumonia-like (acute, cough, fever, SOB) with wt loss, but no sputum and doesn't respond to antibiotics.
    • AIP: Fever, cough, worsening dyspnea over 1-2 weeks, will progress to the inability to breath, CXR shows bilateral diffuse opacities, lung biopsy shows organizing DAD, tx with mechanical ventilation.
  • Immunocompromised
    • PCP: Fever, cough, SOB in immunocompromised, diffuse lung opacities, dx by microscopy (staining, immunofluorescence) of respiratory samples (induced sputum, lavage, biopsy).
    • Pulmonary aspergillosis: Fever, cough, pleuritic chest pain, hemoptysis, hx of immunocompromise, CXR shows lung consolidation with cavitation, dx by serology and culture, tx with voriconazole.
    • CMV (owl's eyes)
    • Herpes (molded nuclei)
  • Neoplasms
    • Lung hamartoma: Solitary peripheral nodule (CXR) made of cartilage and/or fat (biopsy), benign.
    • Lung carcinoma: Cough, SOB, hemoptysis, fatigue, wt loss, smoking hx, CXR shows mass, biopsy shows malignancy.
      • Squamous cell lung carcinoma: central mass, biopsy shows squamous malignancy (desmosomes, keratin).
      • Adenocarcinoma
      • BAC: peripheral mass, nodule, or multiple nodules resembling metastasis, biopsy shows normal lung architecture but alveoli looks like glands.
      • Large cell lung carcinoma: Diagnosis of exclusion: biopsy shows large cells without squamous or glandular morphology.
      • Small cell lung carcinoma: smoker, central mass, biopsy shows small, blue cells, paraneoplastic syndromes (SIADH, ACTH/Cushings).
    • Mesothelioma: pleural mass, effusion, biopsy shows malignancy, EM shows long microvilli, Hx of asbestos exposure.
    • Metastases to the lung: multiple nodules on CXR
  • Vascular
    • Pulmonary embolism: there's a clot (pleuritic pain) - you can't get oxygen (O2↓) no matter how hard you breath (tachypnea, SOB), dx by CT (contrast enhanced).
    • Pulmonary hypertension: Pulm arterial pressure↑ because resistance↑, wedge pressure is normal, causes SOB, fatigue, leads to right heart failure, CXR shows dilated pulm artery.
    • GPA (Wegener's): ENT (sinusitis, crusting), pulm and renal (hemoptysis, hematuria), vasculitis (purpura), due to ANCA, perivascular granulomas, glomerular crescents without immune deposits.
    • Goodpasture's syndrome: Lung (SOB, hemoptysis, diffuse opacities), Renal (hematuria) and fatigue due to anti-GBM - renal biopsy shows crescents and IgG deposition.
  • Sputum
    • Bronchiectasis: cough, muco-purulent sputum, hemoptysis, recurrent sinusitis, CT shows dilated peripheral airways.
    • CF: Recurrent sinusitis, thick sputum, pancreatic insufficiency (steatorrhea), meconium ileus, infertility, dx by sweat chloride↑, CFTR mutation.
    • PCD (Kartagener's): immotile cilia causing recurrent ear/sinus infections, situs inversus, infertility, bronchiectasis, dx by reduced nasal NO and brush biopsy showing immotile cilia.
    • Asthma: allergy (episodic attacks) causes wheeze, cough (esp at night) and SOB, dx with methacholine test, tx with albuterol (acute) and advair (maintenance).
    • COPD (dyspnea): chronic bronchitis (cough+sputum) and emphysema (barrel chest) due to smoking, exertional dyspnea, morning headache, hypoxia.
    • Pneumonia
  • Hemoptysis
    • Bronchiectasis: cough, muco-purulent sputum, hemoptysis, recurrent sinusitis, CT shows dilated peripheral airways.
    • Pulmonary embolism: there's a clot (pleuritic pain) - you can't get oxygen (O2↓) no matter how hard you breath (tachypnea, SOB), dx by CT (contrast enhanced).
    • TB: chest pain, cough, nightsweats, hemoptysis, foreign/abroad/prison hx, apical lung opacities with cavitation.
    • GPA (Wegener's): ENT (sinusitis, crusting), pulm and renal (hemoptysis, hematuria), vasculitis (purpura), due to ANCA, perivascular granulomas, glomerular crescents without immune deposits.
    • Goodpasture's syndrome: Lung (SOB, hemoptysis, diffuse opacities), Renal (hematuria) and fatigue due to anti-GBM - renal biopsy shows crescents and IgG deposition.
    • Lupus: buttefly rash, photosensitivity, fatigue, joint pain (hands) and a whole bunch of organ systems involved - dx by ANA and anti-dsDNA antibodies.
  • Exposure to irritants
    • Hypersensitivity pneumonitis: exposure to farm/organic dust causes cough, SOB, fatigue, CXR shows bilateral diffuse (nodular) infiltrates, biopsy shows loosely formed granulomas and thick alveoli septa.
    • Pneumoconiosis: Restrictive lung disease caused by breathing in various inorganic dusts (asbestos, silica, coal, metals, cotton).
    • Asbestosis: insidious onset of dyspnea with exertion due to hx of asbestos exposure, CXR shows peripheral opacities, pleural plaques, lavage shows asbestos fibers.
    • Silicosis: sand blaster comes in with cough, SOB, chest xray shows nodules located centrally, biopsy shows fibrotic nodules surrounded by macrophages containing silica.
    • COPD (dyspnea): chronic bronchitis (cough+sputum) and emphysema (barrel chest) due to smoking, exertional dyspnea, morning headache, hypoxia.
  • Skin manifestations
    • Sarcoidosis: SOB, hilar adenopathy, skin (face plaques, ankle erythema), arthritis, diffuse opacity on CXR, non-caseating granulomas.
    • GPA (Wegener's): ENT (sinusitis, crusting), pulm and renal (hemoptysis, hematuria), vasculitis (purpura), due to ANCA, perivascular granulomas, glomerular crescents without immune deposits.
    • Lupus: buttefly rash, photosensitivity, fatigue, joint pain (hands) and a whole bunch of organ systems involved - dx by ANA and anti-dsDNA antibodies.
  • Granulomas
    • TB: chest pain, cough, nightsweats, hemoptysis, foreign/abroad/prison hx, apical lung opacities with cavitation.
    • Sarcoidosis: SOB, hilar adenopathy, skin (face plaques, ankle erythema), arthritis, diffuse opacity on CXR, non-caseating granulomas.
    • Hypersensitivity pneumonitis: exposure to farm/organic dust causes cough, SOB, fatigue, CXR shows bilateral diffuse (nodular) infiltrates, biopsy shows loosely formed granulomas and thick alveoli septa.
    • GPA (Wegener's): ENT (sinusitis, crusting), pulm and renal (hemoptysis, hematuria), vasculitis (purpura), due to ANCA, perivascular granulomas, glomerular crescents without immune deposits.
  • Emergency
    • AIP: Fever, cough, worsening dyspnea over 1-2 weeks, will progress to the inability to breath, CXR shows bilateral diffuse opacities, lung biopsy shows organizing DAD, tx with mechanical ventilation.
    • ARDS: shock/sepsis triggers rapid decline in pulmonary function: PaO2↓, O2 sat↓, SOB, tachypnea, CXR shows bilateral diffuse fluffy opacities with air bronchograms, tx with mechanical ventilation.
    • Pneumothorax: acute SOB, pleuritic chest pain, hypoxia, dx by CXR: visceral pleural line (upright, lateral decub), deep sulcus sign (supine), tx with chest tube, needle aspiration.
    • Pulmonary embolism: there's a clot (pleuritic pain) - you can't get oxygen (O2↓) no matter how hard you breath (tachypnea, SOB), dx by CT (contrast enhanced).
  • Effusions
    • Transudate: clear, basic, acellular, less stuff (LDH, protein) than serum.
      • CHF: exertional dyspnea, JVD, peripheral edema, elevated BNP, can be chronic or acute decompensated.
      • Nephrotic syndrome (lipiduria): proteinuria (edema, albumin↓) and lipiduria (fat casts, hyperlipidemia).
      • Cirrhosis with ascites
    • Exudate
      • PMN: pneumonia
      • Lymphocytic: Malignancy, TB
      • Eosinophils: drug, asbestos, parasites
      • Amylase: pancreatitis, esophageal rupture
      • Milky: chylothorax (TGs) or Chyliform (cholesterol from TB, rheum)
  • Radiology
    • Hilar adenopathy
      • Sarcoidosis: SOB, hilar adenopathy, skin (face plaques, ankle erythema), arthritis, diffuse opacity on CXR, non-caseating granulomas.
      • Primary TB: Ghon complex: interlobar granuloma (Ghon focus) + hilar/mediastinal adenopathy, mild symptoms (low-grade fever, chest pain).
    • Central
      • Silicosis: sand blaster comes in with cough, SOB, chest xray shows nodules located centrally, biopsy shows fibrotic nodules surrounded by macrophages containing silica.
      • PCP: Fever, cough, SOB in immunocompromised, diffuse lung opacities, dx by microscopy (staining, immunofluorescence) of respiratory samples (induced sputum, lavage, biopsy).
      • Pulmonary edema
    • Peripheral/subpleural
      • Asbestosis: insidious onset of dyspnea with exertion due to hx of asbestos exposure, CXR shows peripheral opacities, pleural plaques, lavage shows asbestos fibers.
      • IPF: Cough, exertional dyspnea, CXR shows patchy subpleural infiltrates, biopsy shows patches of fibrosis and normal lung (temporal heterogeneity).
      • BOOP: pneumonia-like (acute, cough, fever, SOB) with wt loss, but no sputum and doesn't respond to antibiotics.
    • Upper/apical
      • TB: chest pain, cough, nightsweats, hemoptysis, foreign/abroad/prison hx, apical lung opacities with cavitation.
      • Sarcoidosis: SOB, hilar adenopathy, skin (face plaques, ankle erythema), arthritis, diffuse opacity on CXR, non-caseating granulomas.
      • Silicosis: sand blaster comes in with cough, SOB, chest xray shows nodules located centrally, biopsy shows fibrotic nodules surrounded by macrophages containing silica.
    • Lower/basal
      • Asbestosis: insidious onset of dyspnea with exertion due to hx of asbestos exposure, CXR shows peripheral opacities, pleural plaques, lavage shows asbestos fibers.
      • IPF: Cough, exertional dyspnea, CXR shows patchy subpleural infiltrates, biopsy shows patches of fibrosis and normal lung (temporal heterogeneity).
    • Multiple nodules
      • Metastases to the lung
      • Miliary TB
      • BAC: peripheral mass, nodule, or multiple nodules resembling metastasis, biopsy shows normal lung architecture but alveoli looks like glands.
      • Silicosis: sand blaster comes in with cough, SOB, chest xray shows nodules located centrally, biopsy shows fibrotic nodules surrounded by macrophages containing silica.
      • Hypersensitivity pneumonitis: exposure to farm/organic dust causes cough, SOB, fatigue, CXR shows bilateral diffuse (nodular) infiltrates, biopsy shows loosely formed granulomas and thick alveoli septa.
    • Multiple patches
      • BOOP: pneumonia-like (acute, cough, fever, SOB) with wt loss, but no sputum and doesn't respond to antibiotics.
      • IPF: Cough, exertional dyspnea, CXR shows patchy subpleural infiltrates, biopsy shows patches of fibrosis and normal lung (temporal heterogeneity).
    • Cavitation
      • Lung carcinoma: Cough, SOB, hemoptysis, fatigue, wt loss, smoking hx, CXR shows mass, biopsy shows malignancy.
      • TB: chest pain, cough, nightsweats, hemoptysis, foreign/abroad/prison hx, apical lung opacities with cavitation.
      • GPA (Wegener's): ENT (sinusitis, crusting), pulm and renal (hemoptysis, hematuria), vasculitis (purpura), due to ANCA, perivascular granulomas, glomerular crescents without immune deposits.
      • Simple aspergilloma: mild cough, fungus ball confined to the lung, shows up on CXR.
      • Pulmonary aspergillosis: Fever, cough, pleuritic chest pain, hemoptysis, hx of immunocompromise, CXR shows lung consolidation with cavitation, dx by serology and culture, tx with voriconazole.
  • Other
    • Sleep apnea: Tired during the day because of snoring, apnea at night, risk factors: hypertension, obese, large neck, old, male.