A sleep disorder is a condition that abnormally affects the quality, duration, or behaviour of a person's sleep.
What is going on in the body?
There are many things that can disrupt sleep. More than 100 different sleep disorders have been identified. These disorders fall into four main categories:
What are the signs and symptoms of the condition?
- dyssomnia. This group includes insomnia, the most common sleep disorder, which is trouble falling or staying asleep. It also includes hypersomnia, which is sleeping too much, and sleeping at inappropriate times.
- parasomnia. This involves unusual experiences or behaviours while sleeping.
- sleep disorders connected with medical or psychiatric disorders.
- other sleep problems that do not fall into the above groups.
Sleep disorder symptoms are often specific to the type of disorder. Following are some examples of common sleep disorders:
Some sleep disorders are quite unusual. Narcolepsy, for example, causes sudden attacks of sleep and even paralysis in some affected people. These attacks may occur suddenly, such as while a person is in the middle of a conversation.
- dyssomnia. This includes trouble falling asleep or staying asleep, excessive sleeping or excessive sleepiness during the day, and jet lag.
- parasomnia. This includes people who walk or talk during their sleep, people with nightmares, and people who wet the bed or clench their teeth during sleep.
- sleep disorders due to medical or psychiatric disorders. These include anxiety, depression, psychosis, the use of drugs or alcohol, and pain. Hormonal imbalances and many other medical and psychiatric conditions can impair sleep.
Sleep apnoea has become a well known health hazard and sleep disorder. In this condition, people stop breathing several times during the night for short periods of time. This may cause excessive daytime sleepiness, sleep that is not restful, headaches, and even heart damage.
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:
People who are obese have an increased risk of sleep apnoea. Narcolepsy and some other sleep disorders are thought to have a genetic component to them.
- medications or drugs such as caffeine, nicotine, stimulant drugs, cold medications, sleep medications, and cocaine
- changes in the sleep schedule
- depression and anxiety
- chronic illness or pain
- a poor sleep environment
- excessive daytime napping
What can be done to prevent the condition?
Good sleep habits can prevent many cases from developing. Recommendations from sleep experts include:
Treatment of any underlying psychiatric condition may prevent some sleep problems from occurring. Avoidance of obesity may prevent some cases of sleep apnoea. Some sleep disorders cannot be prevented.
- Don't go to bed unless you are tired.
- Avoid excessive daytime naps. A person should take only one nap a day, if any, and the nap should be less than 1 hour.
- Use the bed only for sex and sleep.
- Wake up at the same time every morning.
- Have a comfortable, dark, quiet sleeping environment.
- Avoid alcohol, caffeine, and other drugs, especially after dinner.
How is the condition diagnosed?
The method for diagnosing sleep disorders depends on the specific problem. A history and physical examination may reveal an underlying condition that can lead to sleeping problems. If an underlying medical condition is suspected, further tests such as blood tests may need to be done.
Special sleep studies are often performed. These involve going to a special "sleep lab", where people are observed while they sleep. Painless electrodes and monitors are attached to the skin to measure brain waves, breathing, heart rate, and other body functions during sleep. The pattern of brain waves and other body functions may be able to determine the sleeping disorder. For example, in sleep apnoea, the person stops breathing several times during the night, often snores, and may have low oxygen levels in their blood when they stop breathing.
What are the long-term effects of the condition?
Not getting enough sleep can harm a person's thinking ability and emotional state. Sleep deprivation can cause problems in:
A person's partner may also be affected. For example, those with sleep apnoea may snore loudly throughout the night, keeping the partner awake. Also, those who don't get enough sleep and are tired are much more likely to get into auto accidents, and could thus seriously harm others.
- short- and long-term memory
- motor co-ordination
- communication, due to fatigue
What are the risks to others?
This condition is not contagious and poses no risk to others.
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, medications can be used. For example, sleeping pills, such as temazepam may be given for insomnia.
The treatment for sleep apnoea involves weight loss for obese persons. The doctor 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 medications used to treat sleep problems can be physically and psychologically addicting. Some may also cause too much sedation and make people groggy or sleepy the next day. Specific side effects depend on the drugs used.
What happens after treatment for the condition?
People are encouraged to continue good sleep habits. The use of any sleeping medications should usually only be for a few weeks or less. If the sleep problem 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?
People should tell their doctor about any changes in sleep patterns. A log can be kept to record how adjustments to lifestyle and medications have affected their sleep.
Author: Ann Reyes, Ph.D.
Reviewer: eknowhow Medical Review Panel
Editor: Dr John Hearne
Last Updated: 12/06/2005
Potential conflict of interest information for reviewers available on request