Obstructive sleep apnea is a common disorder that causes patients to temporarily stop or decrease their breathing repeatedly during sleep. This results in fragmented, nonrestful sleep that can lead to symptoms such as morning headache and daytime sleepiness. Obstructive sleep apnea affects persons of all ages, with an increasing prevalence in those older than 60 years. The exact prevalence is unknown but is estimated to be between 2% and 14%. There are many health conditions associated with obstructive sleep apnea, including hypertension, coronary artery disease, cardiac arrhythmias, and depression. Loud snoring, gasping during sleep, obesity, and enlarged neck circumference are predictive clinical features. Screening questionnaires can be used to assess for sleep apnea, although their accuracy is limited. The diagnostic standard for obstructive sleep apnea is nocturnal polysomnography in a sleep laboratory. Home sleep apnea tests can be performed for certain patients but are generally considered less accurate. Continuous positive airway pressure is the first-line treatment; adherence rates are variable and seem to improve with early patient education and support. Other treatment modalities include weight reduction, oral appliance therapy, and surgery to correct anatomic obstructions, although there is insufficient evidence to support these types of surgeries. Bariatric surgery can improve sleep parameters and symptoms in obese patients with obstructive sleep apnea and can result in remission in many patients.