What is it? 
The two types of sleep apnea 
Obstructive sleep apnea  (OSA) affects primarily men between the ages of 30 and 50. It occurs when air passage in the upper respiratory tract becomes obstructed during sleep (obstruction is caused by soft tissue of the pharynx relaxing and blocking the flow of air). It prevents breathing until low levels of oxygen in the blood cause a person to respond by waking up and taking a deep, snorting breath. Being overweight or having a small tongue or mouth can contribute to the obstruction. In children enlarged tonsils or adenoids are the most common cause of obstruction
Central sleep apnea  is a rare type of sleep apnea where the region of the brain and nerves that regulate breathing do not function normally and cause breathing to be impaired. It can be caused by head injury or stroke.
What are the symptoms? 
Symptoms of both types include: 
Restless sleep Daytime sleepiness Poor memory and concentration Headache in the morning Loud snoring Change in personality Frequent urination during the night  
Who Suffers? 
About 4 - 9 percent of middle-aged men About 2 - 4 percent of middle-aged women About 80 - 90 percent of persons with sleep apnea go undiagnosed  
How is it diagnosed? Your doctor can examine your nose and throat to look for an obstruction in your breathing. You could also have an endoscopy of the nose and throat done and X-rays or a CT scan of the head and neck. You may also have to undergo sleep studies to confirm a diagnosis as variables such as breathing, oxygen levels in the blood and heart rate need to be measured while you are asleep. 
What are its consequences? 
Cardiovascular disease (leading to heart failure, heart attack and stroke) Hypertension (high blood pressure), especially below age 60* Auto accidents: Sufferers of severe sleep apnea are two to three times more likely to be involved in auto accidents than the general population, mainly due to falling asleep while driving  
How is it treated? 
With lifestyle changes and/or appliances Overweight patients should lose weight (even 5 percent can help) Evening alcohol avoidance A Continuous Positive Airway Pressure (CPAP) appliance - a nose mask worn during sleep to prevent airway collapse - is generally effective, but many patients dislike it