Sleep apnea

Obesity is a chronic disease of excess adiposity, defined by a body mass index of 30 or greater, that raises risk for type 2 diabetes, cardiovascular disease, sleep apnea, liver disease, and several cancers. Management is staged: lifestyle intervention for all patients, pharmacotherapy after 3 to 6 months of unmet lifestyle goals, and bariatric surgery for a body mass index of 40 or greater or 35 or greater with a comorbidity.

Essential (primary) hypertension is chronically elevated blood pressure without an identifiable secondary cause, the overwhelming majority of hypertension. It is a leading modifiable driver of stroke, heart failure, and kidney disease, and management combines lifestyle change with staged pharmacotherapy to a target usually below 130/80 mmHg.

Heart failure is a clinical syndrome of impaired cardiac filling or ejection causing congestion and reduced perfusion, classified by ejection fraction. Diagnosis integrates symptoms, signs, natriuretic peptides, and echocardiography, and treatment of reduced-ejection-fraction disease is quadruple guideline-directed therapy, with device therapy and cause-specific management.

Atrial fibrillation is a supraventricular tachyarrhythmia with disorganized atrial activation and an irregularly irregular ventricular response, the most common sustained arrhythmia and a major cause of stroke. Diagnosis is by ECG showing no discrete P waves with irregular RR intervals, and management addresses rate or rhythm control, stroke prevention by CHA2DS2-VASc-guided anticoagulation, and the underlying cause.

Ischemic stroke is sudden focal neurologic deficit from arterial occlusion confirmed by infarction on neuroimaging. Diagnosis relies on urgent noncontrast head CT to exclude hemorrhage; treatment is IV alteplase within 4.5 hours and mechanical thrombectomy for large-vessel occlusion within an extended window, followed by antiplatelet therapy and risk-factor control.

Type 2 diabetes is hyperglycemia from insulin resistance with progressive relative insulin deficiency, diagnosed by a hemoglobin A1c of 6.5% or higher, a fasting glucose of 126 mg/dL or higher, or a 2-hour oral glucose tolerance test value of 200 mg/dL or higher. First-line treatment is lifestyle modification plus metformin, with an SGLT2 inhibitor or GLP-1 receptor agonist added early for patients with atherosclerotic disease, kidney disease, or heart failure.

Pulmonary hypertension is a resting mean pulmonary artery pressure of 20 mmHg or greater on right heart catheterization, classified into five WHO groups by mechanism. Diagnosis requires screening echocardiography followed by confirmatory right heart catheterization, and management is group-specific, with PAH-targeted vasodilator therapy reserved for group 1 disease.

Chronic obstructive pulmonary disease is a persistent, usually progressive airflow obstruction driven mainly by cigarette smoke, confirmed by a postbronchodilator FEV1/forced vital capacity (FVC) ratio below 0.70 and staged by GOLD spirometric grade plus symptom/exacerbation group. Maintenance management is a stepwise ladder of smoking cessation, long-acting bronchodilators, add-on inhaled glucocorticoid, roflumilast, or azithromycin for frequent exacerbators, long-term oxygen for resting hypoxemia, and vaccination, with acute exacerbations managed as a separate protocol.

GERD is retrograde reflux of gastric contents into the esophagus causing heartburn and regurgitation, diagnosed clinically and confirmed by response to an empiric PPI trial, with endoscopy reserved for alarm features or refractory symptoms. Management proceeds from lifestyle measures through an 8-week once-daily PPI trial, dose escalation or agent switch for partial response, and fundoplication for medication-refractory or regurgitation-predominant disease.

Insomnia is difficulty with sleep initiation, maintenance, or quality despite adequate opportunity for sleep, with daytime dysfunction; it becomes chronic insomnia disorder once symptoms occur at least 3 nights per week for at least 3 months. Treat first-line with cognitive behavioral therapy for insomnia, reserving hypnotics such as zolpidem, eszopiclone, or low-dose doxepin for refractory or short-term use.

Narcolepsy is a chronic central disorder of hypersomnolence marked by irresistible, recurrent daytime sleep attacks, most often from loss of orexin (hypocretin) producing neurons in the lateral hypothalamus; cataplexy, when present, is considered pathognomonic. Diagnosis follows a normal overnight polysomnogram and a multiple sleep latency test showing shortened sleep latency and rapid sleep-onset REM. Manage first with scheduled naps and sleep hygiene, then a wakefulness-promoting agent such as modafinil, adding pitolisant or sodium oxybate specifically for cataplexy.