Sleep Apnea

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Medical Author:

Siamak T. Nabili, MD, MPH

Siamak T. Nabili, MD, MPH

Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Sleep Apnea Overview
• Sleep Apnea Causes
• Sleep Apnea Symptoms
• When to Seek Medical Care
• Exams and Tests
• Sleep Apnea Treatment
• Self-Care at Home
• Medical Treatment
• Medication
• Medical Devices
• Surgery
• Follow-up
• Prevention
• Outlook
• Synonyms and Keywords
• Author and Editor
• Read more on Obstructive and Central Sleep Apnea from Healthwise
• Viewer Comments: Sleep Apnea - Effective Treatments

Sleep Apnea Overview

Sleep apnea is a common condition characterized by a periodic reduction in or a complete stop of breathing during sleep. There are two main types of sleep apnea; obstructive sleep apnea (OSA) and central sleep apnea (CSA). Mixed sleep apnea refers to the combination of both central and obstructive sleep apnea.

Apnea is defined as a cessation or near-cessation of breathing for 10 seconds or more that results in a reduction of airflow to 25% below normal. A less severe reduction in breathing is called hypopnea.

The basic underlying mechanism is different for the types of sleep apnea. Normally, the brain sends a signal to the respiratory muscles to expand and bring air into the lungs. In central sleep apnea, the brain fails to send this signal appropriately, causing disrupted and unregulated breathing. In obstructive sleep apnea, the brain sends appropriate signals and the muscles try to expand to initiate breathing, however, the flow of air into the lungs is obstructed, causing reduced breathing and airflow into the lungs.

In general, sleep apnea is rare in children. It becomes more prevalent with increasing age and it is more common in men than women. Obstructive sleep apnea is more common than central sleep apnea. It is estimated that about 25% of adults are at risk for developing obstructive sleep apnea. It is also estimated that up to 4% of adults may have central sleep apnea. These conditions remain somewhat under-diagnosed in the general population.

Sleep apnea may lead to disrupted sleep, daytime sleepiness, and insomnia. If untreated, sleep apnea may contribute to other medical conditions, such as high blood pressure (hypertension), congestive heart failure, pulmonary hypertension, heart disease, strokes, or even death.