Obstructive sleep apnea is a condition where sleep is interrupted by abnormal breathing. In sleep apnea, breathing is interrupted by the airway blocking the flow of air. These interruptions last for longer than 10 seconds and happen at least 5 times an hour throughout your sleep period. When your breathing is reduced and you're not taking in enough oxygen, it's called hypopnea. If your breathing completely stops, it's called apnea. Obstructive sleep apnea can range from mild to severe. This is based on a measurement rating system called the apnea-hypopnea index (AHI). The AHI measures an average number of apnea and hypopnea episodes you have per hour that you sleep.

In adults, obstructive sleep apnea is classified by how bad it is:

• Severe obstructive sleep apnea means that your AHI is greater than 30. You have more than 30 episodes per hour.
• Moderate obstructive sleep apnea means that your AHI is between 15 and 30.
• Mild obstructive sleep apnea means that your AHI is between 5 and 15.
• Normal sleep means that your AHI is less than five.

When you sleep, your body is completely relaxed. This even includes the muscles that help you breathe. In people with sleep apnea, these relaxed muscles combine with a narrowed airway to interrupt breathing.

Anyone at any age can have obstructive sleep apnea. But it's most common in middle-aged and older adults. Only about 1 in 50 children have obstructive sleep apnea. It's also more common in men than in women.

But what's frightening is that as many as 9 in 10 people who have obstructive sleep apnea don't know that they have it. Untreated, sleep apnea can lead to serious health problems.

Knowing the risk factors for obstructive sleep apnea can help you get a diagnosis. Risk factors include:

• Family member with obstructive sleep apnea
• Large or thick neck. This means greater than 16 inches for women and 17 inches for men.
• Long-term (chronic) nasal congestion
• Thyroid disorder or other endocrine condition
• Postmenopause
• Being overweight
• Defect of the tissues that support the head and neck
• Down syndrome
• Smoking
• Swollen or large adenoids and tonsils (in children)

Some people have obstructive sleep apnea with no symptoms. Others find that they just don't feel rested after a night of sleep. They feel sleepy during the day.

Snoring is one of the biggest symptoms of obstructive sleep apnea. Other symptoms include:

• Snoring that's interrupted with periods of quiet. This is called an apnea episode.
• Snoring that resumes with a loud sound as breathing starts again
• Morning headache
• Frequently falling asleep during the day
• Having to wake up during the night to urinate several times
• Being easily irritated
• Depression
• Trouble remembering things

A diagnosis of obstructive sleep apnea needs a sleep study. During a sleep study, you're kept track of as you sleep. Your sleep study may either be done in a special facility (his is called an in-lab sleep study), or at home (this is called a home sleep study).

Your doctor will also do a physical exam. This includes an exam of the throat, neck, and mouth. The doctor will also ask about your health history. You'll probably also have to answer questions about your sleep and bedtime routine, as well as your symptoms. Your doctor may have you do blood tests to rule out conditions similar to sleep apnea, such as a low thyroid level.

These are common treatments to keep your breathing consistent and stop or reduce apnea episodes:

• Sleeping with a CPAP (continuous positive airway pressure) machine and mask. This treatment gives a constant flow of air to help keep your airway open.
• Wearing an oral appliance. This is a custom-fit mouthpiece your dentist or orthodontist can make for you to keep airways open while you sleep.

Several types of surgery can be done to treat obstructive sleep apnea:

• Surgery to repair problems in facial structures
• Surgery to get rid of extra tissues that can block airways
• Surgery to repair problems that cause obstructions when you breathe or to create a wider airway
• Removal of adenoids and tonsils. This works best in children.
• Implanting nerve stimulators. These make the muscle strong and prevent airway collapse while sleeping.

Making a few changes to your sleep and other behaviors can also help manage obstructive sleep apnea:

• Work with your doctor to lose weight, if needed.
• Sleep on your side instead of on your back.
• Don't drink alcohol.
• Limit or eliminate your use of sedatives.

Letting obstructive sleep apnea continue untreated is risky. You can get in a serious accident if you fall asleep while operating machinery or driving a car due to being so tired from sleep apnea.

Health problems may develop as a result of obstructive sleep apnea. These include:

• Increased blood pressure
• Unstable oxygen levels
• Changes in your body's response to insulin and glucose
• Changes in mental function and mood
• Cardiovascular problems, such as heart failure, stroke, or heartbeat problems (arrhythmia)

Don't do things that relax your muscles. For example, don't drink alcohol or take sedatives to help you sleep. And stay at a healthy weight.

Contact your doctor if your bed partner hears symptoms of apnea episodes or your snoring is causing problems. Ask your doctor about a sleep study. Feeling drowsy or falling asleep often during the day are also signs that you should call your doctor.

• Obstructive sleep apnea means your breathing is interrupted during sleep. This can happen many times an hour.
• Snoring that's interrupted with periods of quiet is one of the main symptoms of obstructive sleep apnea.
• You will probably need a sleep study to help diagnose obstructive sleep apnea. This means you will be kept track of while you sleep, either at a hospital or a sleep center. Or you will use a recording device in your home.
• If not treated, obstructive sleep apnea can put you at risk for major health problems. These can include heart failure and high blood pressure.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours and on weekends and holidays.