You have sleep apnea when your breathing is often blocked or partly blocked while you sleep. It can be mild, moderate, or severe, depending on the number of times an hour that you have less airflow to your lungs. For adults, apnea may occur from 5 times an hour to more than 30 times an hour.

The most common form of sleep apnea is obstructive sleep apnea. Although doctors use sleep studies to diagnose both obstructive sleep apnea and central sleep apnea, this Decision Point focuses on obstructive sleep apnea.

Obstructive sleep apnea happens when the airways in your nose, mouth, or throat are blocked or become narrow. Everyone's throat muscles and tongue relax during sleep. But in some people, certain things can cause this normal process to partly or completely block the airway.

Symptoms of sleep apnea can include:

• Being so sleepy during the day that it gets in the way of the normal things you do, such as work or school.
• Feeling tired in the morning.
• Having trouble concentrating.
• Waking up with a headache.

Your bed partner may notice that while you sleep:

• You stop breathing.
• You often snore loudly.
• You gasp or choke.
• You toss and turn.

Snoring and lack of sleep from apnea can make it hard to get through the day. You may feel grouchy a lot and have trouble focusing on work and activities. If you snore, your bed partner also might not get enough sleep. This can make your relationship suffer.

A sleep study is the only sure way to know if you have sleep apnea. The main type is an all-night sleep study done in a qualified sleep lab. It is called polysomnography (say "pawl-ee-sawm-NAW-gruh-fee"). Sleep studies also can be done with portable equipment that you use at home.

You might want a sleep study, because if you have sleep apnea and it's not found and treated, it can interfere with your quality of life. It can make you too sleepy when you should be awake.

It also is linked to problems such as:

• High blood pressure.
• High blood pressure in the lungs (pulmonary hypertension).
• Depression.
• Irregular heart rhythms.
• Heart failure.
• Coronary artery disease.
• Stroke.

If you snore but don't have other symptoms, you may not need a sleep study. Lifestyle changes—such as losing weight (if needed) and sleeping on your side—may reduce your snoring.

Treatment for sleep apnea can include:

• Lifestyle changes, such as losing weight (if needed), sleeping on your side, avoiding alcohol and sedating medicines before bedtime, and not smoking.
• Continuous positive airway pressure (CPAP). This uses a machine to keep your airway open while you sleep.
• Oral breathing devices or other types of devices that you wear while you sleep to help keep your airway open.
• Surgery to open your airway.

Your doctor probably will have you try lifestyle changes and CPAP first. But surgery might be your first choice if your sleep apnea is caused by a blockage that can be fixed easily.

Sleep apnea can make it hard for you to get good rest. It can make you tired during the day, and it can cause serious health problems. But treatment, like lifestyle changes, breathing machines, or oral or nasal breathing devices, can help. Breathing better at night can help you feel better during the day.

Your doctor might recommend a sleep study if:

• You have symptoms of sleep apnea, such as heavy snoring and being sleepy during the day.
• You have a risk of other health problems from sleep apnea.
• Lack of sleep is hurting your quality of life or raising safety issues.