Sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and starts. You may have sleep apnea if you snore loudly and you feel tired even after a full night's sleep.

Sleep apnea occurs in two main types:

• Obstructive sleep apnea, the more common form that occurs when throat muscles relax
• Central sleep apnea, which occurs when your brain doesn't send proper signals to the muscles that control breathing
• Additionally, some people have complex sleep apnea, which is a combination of both.

If you think you might have sleep apnea, see your doctor. Treatment is necessary to avoid heart problems and other complications.

What are the Symptoms of Sleep Apnea

The signs and symptoms of obstructive and central sleep apneas overlap, sometimes making the type of sleep apnea more difficult to determine.

The most common signs and symptoms of obstructive and central sleep apneas include:

• Excessive daytime sleepiness (hypersomnia)
• Loud snoring, which is usually more prominent in obstructive sleep apnea
• Observed episodes of breathing cessation during sleep
• Abrupt awakenings accompanied by shortness of breath, which more likely indicates central sleep apnea
• Awakening with a dry mouth or sore throat
• Morning headache
• Difficulty staying asleep (insomnia)

When to see a doctor

Consult a medical professional if you experience, or if your partner observes, the following:

• Snoring loud enough to disturb the sleep of others or yourself
• Shortness of breath that awakens you from sleep
• Intermittent pauses in your breathing during sleep
• Excessive daytime drowsiness, which may cause you to fall asleep while you're working, watching television or even driving

Many people don't think of snoring as a sign of something potentially serious, and not everyone who has sleep apnea snores. But be sure to talk to your doctor if you experience loud snoring, especially snoring that's punctuated by periods of silence.

Ask your doctor about any sleep problem that leaves you chronically fatigued, sleepy and irritable. Excessive daytime drowsiness (hypersomnia) may be due to other disorders, such as narcolepsy.

What Causes Sleep Apnea?

Obstructive sleep apnea occurs when the muscles in the back of your throat relax. These muscles support the soft palate, the triangular piece of tissue hanging from the soft palate (uvula), the tonsils and the tongue.

When the muscles relax, your airway narrows or closes as you breathe in, and breathing momentarily stops. This may lower the level of oxygen in your blood. Your brain senses this inability to breathe and briefly rouses you from sleep so you can reopen your airway. This awakening is usually so brief that you don't remember it.

You can awaken with a transient shortness of breath that corrects itself quickly, within one or two deep breaths, although this is rare. You may make a snorting, choking or gasping sound. This pattern can repeat itself five to 30 times or more each hour, all night long. These disruptions impair your ability to reach the desired deep, restful phases of sleep, and you'll probably feel sleepy during your waking hours.

People with obstructive sleep apnea may not be aware that their sleep was interrupted. In fact, many people with this type of sleep apnea think they sleep well all night.

What Causes Central Sleep Apnea

Central sleep apnea, which is much less common, occurs when your brain fails to transmit signals to your breathing muscles. You may awaken with shortness of breath or have a difficult time getting or staying asleep. Like with obstructive sleep apnea, snoring and daytime sleepiness can occur. The most common cause of central sleep apnea is heart disease and, less commonly, a stroke. People with central sleep apnea may be more likely to remember awakening than are people with obstructive sleep apnea.

Causes of Complex Sleep Apnea

People with complex sleep apnea have upper airway obstruction just like those with obstructive sleep apnea, but they also have a problem with the rhythm of breathing and occasional lapses of breathing effort.

What Sleep Apnea Treatments are Available?

For milder cases of sleep apnea, your doctor may recommend lifestyle changes, such as losing weight or quitting smoking. If these measures don't improve your signs and symptoms or if your apnea is moderate to severe, a number of other treatments are available. Certain devices, such as a Continuous Positive Airway Pressure (CPAP) mask, can help open up a blocked airway. In other cases, surgery may be necessary.

Preparing for Your Appointment

If it's suspected that you have sleep apnea, you're likely to start by seeing your family doctor or a general practitioner. However, in some cases when you call to set up an appointment, you may be referred immediately to a sleep specialist.

Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.

Information to Gather in Advance

• Write down your symptoms, including when they first started and when they tend to occur.
• Write down your key medical information, other conditions with which you've been diagnosed and any prescription or over-the-counter medications you're taking, including vitamins and supplements. Also note whether you or anyone in your family has a history of sleep apnea.
• Take a family member or friend along, if possible. Sometimes it can be difficult to soak up all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
• Write down questions to ask your doctor. Creating your list of questions in advance can help you make the most of your time with your doctor.

Below are some basic questions to ask your doctor about sleep apnea. If any additional questions occur to you during your visit, don't hesitate to ask.

• What is the most likely cause of my signs and symptoms?
• Are there any other possible causes?
• What tests are needed to make a diagnosis?
• What treatment options are available for this condition?
• If you're recommending medications, what are the possible side effects?
• I have these other health conditions. How can I best manage them together?
• What self-care steps are likely to improve my symptoms?
• Can you recommend any educational materials for me to take home or look up on the Web?
• Where can I find a support group for people with sleep disorders?

What You Can Do in the Meantime

• Try to sleep on your side. Most forms of sleep apnea are milder when you sleep on your side.
• Avoid alcohol close to bedtime. Alcohol worsens obstructive and complex sleep apnea.
• If you're drowsy, avoid driving. If you have sleep apnea you may be abnormally sleepy, which can put you at higher risk of motor vehicle accidents. At times, a close friend or family member might tell you that you appear sleepier than you feel. If this is true, try to avoid driving at all.

Your doctor may make an evaluation based on your signs and symptoms or may refer you to a Sleep Disorder Center. There, a Sleep Specialist can help you decide on your need for further evaluation. Such an evaluation often involves overnight monitoring of your breathing and other body functions during sleep.

If you have Obstructive Sleep Apnea, your doctor may refer you to an ear, nose and throat doctor (otolaryngologist) to rule out any blockage in your nose or throat. An evaluation by a heart doctor (cardiologist) or a doctor who specializes in the nervous system (neurologist) may be necessary to look for causes of central sleep apnea.