Overview

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.

The main types of sleep apnea are:

  • 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.
  • Complex sleep apnea syndrome, also known as treatment-emergent central sleep apnea, occurs when someone has both obstructive sleep apnea and central sleep apnea.

If you think you might have any form of sleep apnea, see your doctor. Treatment can ease your symptoms and may help prevent heart problems and other complications.

Symptoms

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:

  • Loud snoring, which is usually more prominent in obstructive sleep apnea
  • Episodes of breathing cessation during sleep witnessed by another person
  • 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)
  • Excessive daytime sleepiness (hypersomnia)
  • Attention problems
  • Irritability

When to see a doctor

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

  • Snoring loud enough to disturb the sleep of others or yourself
  • Shortness of breath, gasping for air or choking 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 sleep apnea or to other disorders, such as narcolepsy.

Causes

Causes of obstructive 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, the side walls of the throat and the tongue.

When the muscles relax, your airway narrows or closes as you breathe in, and you can't get an adequate breath in. This may lower the level of oxygen in your blood.

Your brain senses this inability to breathe and briefly rouses you from sleep so that you can reopen your airway. This awakening is usually so brief that you don't remember it.

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, some people with this type of sleep apnea think they sleep well all night.

Causes of central sleep apnea

Central sleep apnea is a less common form of sleep apnea that occurs when your brain fails to transmit signals to your breathing muscles. This means you make no effort to breathe for a short period of time. You may awaken with shortness of breath or have a difficult time getting to sleep or staying asleep.

Risk factors

Sleep apnea can affect anyone, even children. But certain factors increase your risk of sleep apnea:

Obstructive sleep apnea

  • Excess weight. People who are obese have four times the risk of sleep apnea that people who are a normal weight people do. Fat deposits around your upper airway may obstruct your breathing. But not everyone who has sleep apnea is overweight.
  • Neck circumference. People with thicker necks may have narrower airways. For men, the risk increases if neck circumference is 17 inches (43 centimeters) and larger. In women, the risk increases if neck circumference is 15 inches (38 centimeters) or more.
  • A narrowed airway. You may have inherited a naturally narrow throat. Or, tonsils or adenoids may become enlarged and block the airway, particularly in children with sleep apnea.
  • Being male. Men are twice as likely to have sleep apnea. However, women increase their risk if they're overweight, and their risk also appears to rise after menopause.
  • Being older. Sleep apnea occurs significantly more often in older adults.
  • Family history. If you have family members with sleep apnea, you may be at increased risk.
  • Use of alcohol, sedatives or tranquilizers. These substances relax the muscles in your throat.
  • Smoking. Smokers are three times more likely to have obstructive sleep apnea than are people who've never smoked. Smoking may increase the amount of inflammation and fluid retention in the upper airway. This risk likely drops after you quit smoking.
  • Nasal congestion. If you have difficulty breathing through your nose — whether it's from an anatomical problem or allergies — you're more likely to develop obstructive sleep apnea.

Central sleep apnea

  • Being older. Middle-aged and older people have a higher risk of central sleep apnea.
  • Heart disorders. People with congestive heart failure are more at risk of central sleep apnea.
  • Using narcotic pain medications. Opioid medications, especially long-acting ones such as methadone, increase the risk of central sleep apnea.
  • Stroke. People who've had a stroke are more at risk of central sleep apnea or treatment-emergent central sleep apnea.

Complications

Sleep apnea is considered a serious medical condition. Complications may include:

  • Daytime fatigue. The repeated awakenings associated with sleep apnea make normal, restorative sleep impossible. People with sleep apnea often experience severe daytime drowsiness, fatigue and irritability.

    You may have difficulty concentrating and find yourself falling asleep at work, while watching TV or even when driving. People with sleep apnea have an increased risk of motor vehicle and workplace accidents.

    You may also feel quick tempered, moody or depressed. Children and adolescents with sleep apnea may do poorly in school or have behavior problems.

  • High blood pressure or heart problems. Sudden drops in blood oxygen levels that occur during sleep apnea increase blood pressure and strain the cardiovascular system. If you have obstructive sleep apnea, your risk of high blood pressure (hypertension) is greater than if you don't.

    Obstructive sleep apnea may increase the risk of recurrent heart attack, and abnormal heartbeats, such as atrial fibrillation. Obstructive sleep apnea also increases the risk of stroke. If there's underlying heart disease, these multiple episodes of low blood oxygen (hypoxia or hypoxemia) can lead to sudden death from an irregular heartbeat.

  • Type 2 diabetes. People with sleep apnea are more likely to develop insulin resistance and type 2 diabetes compared with people without the sleep disorder.
  • Metabolic syndrome. This disorder is a collection of other risk factors linked to a higher risk of heart disease. The conditions that make up metabolic syndrome include high blood pressure, abnormal cholesterol, high blood sugar and an increased waist circumference.
  • Complications with medications and surgery. Obstructive sleep apnea is also a concern with certain medications and general anesthesia. People with sleep apnea may be more likely to experience complications following major surgery because they're prone to breathing problems, especially when sedated and lying on their backs. Before you have surgery, tell your doctor that you have sleep apnea and how it's treated.
  • Liver problems. People with sleep apnea are more likely to have abnormal results on liver function tests, and their livers are more likely to show signs of scarring. This is a condition known as nonalcoholic fatty liver disease.
  • Sleep-deprived partners. Loud snoring can keep those around you from getting good rest and eventually disrupt your relationships. It's not uncommon for a partner to go to another room, or even on another floor of the house, to be able to sleep. Many bed partners of people who snore may be sleep-deprived as well.