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.