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
- 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)
- Attention problems
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 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.
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 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, 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 to sleep or staying asleep. Like with obstructive sleep apnea, snoring and daytime sleepiness can occur. The most common cause of central sleep apnea is heart failure and, less commonly, a stroke. People with central sleep apnea may be more likely to remember awakening than are people with obstructive sleep apnea.
Sleep apnea can affect anyone. Even children can have sleep apnea. But certain factors put you at increased risk:
Obstructive sleep apnea
- Excess weight. Fat deposits around your upper airway may obstruct your breathing. However, not everyone who has sleep apnea is overweight. Thin people develop this disorder, too.
- Neck circumference. People with a thicker neck may have a narrower airway.
- A narrowed airway. You may have inherited a naturally narrow throat. Or, your tonsils or adenoids may become enlarged, which can block your airway.
- 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 adults older than 60.
- Family history. If you have family members with sleep apnea, you may be at increased risk.
- Race. In people under 35 years old, blacks are more likely to have obstructive sleep apnea.
- 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 male. Males are more likely to develop central sleep apnea.
- Being older. People older than 65 years of age have a higher risk of having central sleep apnea, especially if they also have other risk factors.
- Heart disorders. People with atrial fibrillation or congestive heart failure are more at risk of central sleep apnea.
- Stroke or brain tumor. These conditions can impair the brain's ability to regulate breathing.
Sleep apnea is considered a serious medical condition. Complications may include:
- 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. The more severe your sleep apnea, the greater the risk of high blood pressure. However, obstructive sleep apnea increases the risk of stroke, regardless of whether or not you have high blood pressure. If there's underlying heart disease, these multiple episodes of low blood oxygen (hypoxia or hypoxemia) can lead to sudden death from a cardiac event. Studies also show that obstructive sleep apnea is associated with increased risk of atrial fibrillation, congestive heart failure and other vascular diseases. In contrast, central sleep apnea usually is the result, rather than the cause, of heart disease.
- 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. You may also feel irritable, moody or depressed. Children and adolescents with sleep apnea may do poorly in school or have behavior problems.
- 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. Undiagnosed sleep apnea is especially risky in this situation.
- 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.
- 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 are sleep-deprived as well.
People with sleep apnea may also complain of memory problems, morning headaches, mood swings or feelings of depression, a need to urinate frequently at night (nocturia), and a decreased interest in sex. Children with untreated sleep apnea may be hyperactive and may be diagnosed with attention-deficit/hyperactivity disorder (ADHD).