What is sleep apnea? Sleep apnea is the name of a common disease characterized by interruption of breathing during sleep. This interruption of breathing causes an abnormal blood oxygen level, resulting in fatigue, as well as cardiovascular, cognitive and emotional disorders. Sleep apnea is a common sleep disorder in the United States. The disease is more common in men, African Americans, Hispanics, and Pacific Islanders than in other groups. Further, at least one in 10 people older than 65 has sleep apnea (Source: NHLBI). Sleep apnea occurs due to two causes: obstruction of the airways and irregular brain signals. Most commonly, people develop sleep apnea from relaxation of soft tissue in the back of the throat that blocks the passage of air, resulting in obstructive sleep apnea (OSA). Central sleep apnea (CSA) is caused by irregularities in the brain’s normal signals to breathe. The signs and symptoms of sleep apnea can last indefinitely or come and go. The disease course varies among individuals. Some people with sleep apnea have no symptoms, while others may have severe problems with sleep, decreases in blood oxygen levels (hypoxia), difficulty concentrating, irritability, and fatigue. Fortunately, sleep apnea can be treated successfully with lifestyle changes, breathing devices, and, in severe cases, surgery. Seek immediate medical care (call 911) for serious symptoms, such as chest pain, headache, shortness of breath, severe sweating, or weakness or numbness on one side of the body.