Sleep apnea is a sleep disorder in which a person's breathing repeatedly stops and starts during sleep. There are three main types of sleep apnea: obstructive sleep apnea, central sleep apnea, and complex sleep apnea syndrome.

The most common symptoms of sleep apnea include loud snoring, gasping or choking during sleep, daytime sleepiness, morning headaches, irritability, and difficulty concentrating.

Obstructive sleep apnea is caused by a physical blockage in the airway, such as the collapsing of the soft tissues in the back of the throat. Central sleep apnea is caused by a problem with the brain's respiratory control center, which fails to send proper signals to the muscles that control breathing. Complex sleep apnea syndrome is a combination of both obstructive and central sleep apnea.

Sleep apnea is typically diagnosed through a sleep study, also known as a polysomnography. During a sleep study, various bodily functions are monitored while the patient sleeps, including brain activity, eye movement, muscle activity, heart rate, and breathing patterns.

The most common treatment for sleep apnea is continuous positive airway pressure (CPAP), which involves wearing a mask over the nose and/or mouth during sleep to deliver a constant stream of air to keep the airway open. Other treatments may include dental devices to reposition the jaw, surgery to remove excess tissue in the throat, and lifestyle changes such as weight loss and avoiding alcohol and sedatives.