Overview, Causes, & Risk Factors
A sleep disorder is a condition that abnormally affects the quality, duration, or behavior of a person's sleep.
What is going on in the body?
Sleep disorders fall into three general categories:
primary sleep disorders
disorders secondary to a mental disorder
other sleep disorders, which are related to a medical condition or substance abuse
Primary sleep disorders are caused by some sort of internal disturbance in the sleep-wake cycle. They are categorized as dyssomnias or parasomnias. Dyssomnias involve abnormalities in the amount, quality, or timing of sleep. Common dyssomnias include:
circadian rhythm sleep disorder, which involves a resetting of the body's sleep clock
hypersomnia, which is sleeping too much and sleeping at the wrong times
narcolepsy, which involves a sudden, overwhelming need to sleep at all times of the day
primary insomnia, which is trouble falling or staying asleep
sleep apnea, a condition in which breathing stops during sleep
Parasomnias involve unusual behaviors or body events associated with sleep. These include:
nightmare disorders, which involve frightening dreams
sleep terrors, which involve abrupt awakening and intense fear
Sleep disorders may also be part of a mental disorder, such as anxiety or depression. Other sleep disorders may be caused by medical conditions, such as hormonal imbalances. They may be caused by abuse of substances, such as cocaine or alcohol.
What are the causes and risks of the condition?
Each sleep disorder has its own causes and risk factors. However, the following things worsen most sleep disorders:
changes in the sleep schedule
chronic illness or pain
depression and anxiety
drugs, such as caffeine, nicotine, and cocaine
excessive daytime napping
medicines, such as stimulants, cold medicines, and sleep medicines
a poor sleep environment
People who are obese have an increased risk of sleep apnea. Narcolepsy and some other sleep disorders are thought to have a genetic component.
Symptoms & Signs
What are the signs and symptoms of the condition?
Each sleep disorder has its own characteristic symptoms.
Diagnosis & Tests
How is the condition diagnosed?
Diagnosis of a sleep disorder begins with a medical history and physical exam. If an underlying medical condition is suspected, further tests such as blood tests may need to be done.
A sleep study, called a polysomnogram, may be recommended. This test measures the following body functions during sleep:
airflow and respiratory effort
blood oxygen levels
blood pressure and heart rate
electrical activity in the brain
A multiple sleep latency test measures the speed of falling asleep. An arterial blood gas test may also be performed to check levels of carbon dioxide and oxygen.
Prevention & Expectations
What can be done to prevent the condition?
Good sleep habits can prevent many cases from developing. Here are some recommendations from sleep experts.
Avoid alcohol, caffeine, and other drugs, especially after dinner.
Avoid excessive daytime naps. A person should take only one nap a day, if any, and the nap should be less than 1 hour.
Don't go to bed unless you are tired.
Have a comfortable, dark, quiet sleeping environment.
Use the bed only for sex and sleep.
Wake up at the same time every morning.
Treatment of any underlying psychiatric condition may prevent some sleep problems from occurring. Weight management may prevent some cases of sleep apnea. Some sleep disorders cannot be prevented.
What are the long-term effects of the condition?
Sleep deprivation can lower a person's quality of life and increase the risk for accidents. Up to 50% of the individuals with sleep apnea have high blood pressure. They are also at increased risk for the following disorders:
arrhythmia, or irregular heart rhythm, which may be fatal
cor pulmonale, or enlargement and weakening of the right side of the heart
pulmonary hypertension, or high blood pressure in the lungs
What are the risks to others?
Sleep disorders are not contagious and pose no risk to others.
Treatment & Monitoring
What are the treatments for the condition?
Treatments vary depending upon the specific sleep disorder. Sleep disorder clinics often help people return to normal sleep patterns. Sometimes, sleep disorders go away by themselves. Other times, medicines can be used. For example, sleeping pills, such as zolpidem, zaleplon, or temazepam, may be given for insomnia.
The treatment for sleep apnea involves weight loss for obese persons. The healthcare provider may also prescribe a CPAP machine, a special type of breathing machine used during sleep.
The treatment of narcolepsy involves the use of powerful stimulant drugs, such as dextroamphetamine, to keep people awake during the day. Other treatments are also used, depending on the disorder.
What are the side effects of the treatments?
Some medicines used to treat sleep problems can be physically and psychologically addicting. They may cause daytime drowsiness.
What happens after treatment for the condition?
A sleep disorder may return if the person doesn't continue good sleep habits. If the sleep apnea is improved by weight loss, it's important that the individual keep the excess weight off. Some treatments, such as the use of a CPAP machine, are lifelong. The use of any sleeping medicines should usually only be for a few weeks or less. If the sleep disorder goes away, no further treatment is needed. Some sleep conditions, such as narcolepsy, may need ongoing treatment for prolonged periods of time.
How is the condition monitored?
A log can be kept to record how adjustments to lifestyle and medicines have affected a person's sleep. Any new or worsening symptoms should be reported to the healthcare provider.