Hemoptysis

Massive hemoptysis is bleeding exceeding 100 mL/hour or 150-600 mL over 24 hours with respiratory or hemodynamic compromise, an airway emergency managed by lateral positioning and early intubation, then bronchoscopic localization or CT angiography, and definitive hemostasis with bronchial artery embolization or rigid bronchoscopy.

Bronchiectasis is chronic, irreversible bronchial dilation from a cycle of infection, inflammation, and airway destruction, diagnosed by high-resolution CT and managed with airway clearance, treatment of the underlying cause, and antibiotics for exacerbations.

Lung cancer is the leading cause of cancer death worldwide, split into non-small cell lung cancer (NSCLC, 80% of cases: adenocarcinoma, squamous cell, large cell) and small cell lung cancer (SCLC, 10-15%), both driven overwhelmingly by cigarette smoking. Diagnosis requires tissue histopathology, staging drives treatment (TNM staging for NSCLC, limited versus extensive stage for SCLC), and management ranges from lobectomy in early-stage disease through concurrent chemoradiation and consolidation immunotherapy in locally advanced disease to targeted tyrosine kinase inhibitors, immune checkpoint inhibitors, or platinum-based chemotherapy in metastatic disease.

Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading global cause of infectious death and presents as latent infection, primary/secondary pulmonary disease, or extrapulmonary and disseminated (miliary) disease. Diagnosis rests on AFB smear, NAAT, and mycobacterial culture (the gold standard), and drug-susceptible active disease is treated with a four-drug regimen (isoniazid, rifampin, pyrazinamide, ethambutol) for 2 months followed by isoniazid plus rifampin for 4 to 7 months.

Pulmonary embolism is thrombus, usually from a lower-extremity deep vein thrombosis, obstructing the pulmonary arterial circulation and causing V/Q mismatch, right ventricular strain, and hypoxemia. Diagnosis follows Wells criteria (with PERC in low-risk patients) to sequence D-dimer, CT pulmonary angiography, and V/Q scanning, and management is risk-stratified anticoagulation escalating to thrombolysis or embolectomy for hemodynamic instability.

Mitral stenosis is obstruction of left atrial emptying from a narrowed mitral valve, overwhelmingly rheumatic in origin. It causes left atrial hypertension, atrial fibrillation, and pulmonary congestion, with a diastolic rumble and opening snap; severe symptomatic disease is treated with percutaneous balloon valvuloplasty or valve surgery.

Anti-glomerular basement membrane (anti-GBM) disease is a rare, rapidly progressive glomerulonephritis caused by circulating antibodies against the alpha-3 chain of type IV collagen, presenting with hematuria, acute kidney injury, and, in over half of patients, pulmonary hemorrhage (Goodpasture syndrome). Kidney biopsy showing crescentic glomerulonephritis with linear IgG staining plus a positive serum anti-GBM antibody confirms the diagnosis, and outcome depends critically on early treatment with plasma exchange, pulse glucocorticoids, and cyclophosphamide before dialysis dependence and diffuse crescents set in.

Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody (ANCA)-associated necrotizing granulomatous vasculitis of the upper airway, lower airway, and kidney, most often with cytoplasmic ANCA (c-ANCA) targeting proteinase 3 (PR3). Diagnosis rests on the clinical triad, ANCA serology, and tissue biopsy showing pauci-immune vasculitis, and treatment begins with high-dose glucocorticoids plus rituximab or cyclophosphamide for organ-threatening disease, followed by rituximab or azathioprine maintenance.

Hereditary hemorrhagic telangiectasia is an autosomal dominant vascular dysplasia, most often from ENG or ACVRL1 mutations, causing mucocutaneous telangiectasias and visceral arteriovenous malformations diagnosed by the Curacao criteria. Management combines iron repletion and epistaxis control with lifelong screening and embolization of pulmonary arteriovenous malformations to prevent paradoxical stroke and brain abscess.

Nosebleed from the anterior Kiesselbach plexus or the posterior sphenopalatine artery territory, managed with a stepwise escalation from first aid through cautery, packing, and, for refractory bleeding, embolization or surgical ligation.

Acute bronchitis is a self-limited lower respiratory tract infection causing cough lasting more than five days after other upper respiratory symptoms resolve, almost always viral, and diagnosed clinically after pneumonia is excluded. Management is symptomatic; antibiotics do not shorten the illness and should be withheld absent signs of pneumonia or pertussis.

Cystic fibrosis is an autosomal recessive CFTR chloride-channel disorder causing thick secretions, bronchiectasis, and exocrine pancreatic insufficiency, diagnosed by elevated sweat chloride confirmed with CFTR genotyping and managed with CFTR modulators, airway clearance, and pancreatic enzyme replacement.