Insomnia Health Article

Definition

Insomnia is a condition that occurs when a person in unable to get long enough or refreshing enough sleep at night. Insomnia can result from an inability to fall asleep, an inability to stay asleep, or waking too early before having gotten enough sleep.

Description

Insomnia is a disorder in which people are unable to get enough, or enough restorative, sleep because of one or more factors. People with insomnia often have daytime symptoms related to a lack of sleep, such as daytime sleepiness, fatigue, and decreased mental clarity.

There are two main types of insomnia. One is acute insomnia (sometimes called transient insomnia). This type occurs when insomnia symptoms exist over a reasonably short period of time. The other type is chronic insomnia, which is diagnosed when the symptoms manifest themselves over a longer period (generally more than one month). Insomnia can also be classified as either primary or secondary. Primary insomnia is a disorder that cannot be attributed to another condition or disorder. Secondary insomnia can be traced back to a source, which may be a medical condition; the use of medications, alcohol, or other substances; or a mental disorder such as severe depression.

Not all disruptions in the normal pattern of sleeping and waking are considered insomnia. Such factors as jet lag, unusually high levels of stress, changing work shifts, or other drastic changes in the person's routine can all lead to sleep problems. Unless the problems are ongoing and severe enough that they are causing distress for the person in important areas of life, he or she is not considered to have insomnia.

Causes and symptoms

The symptoms of insomnia can vary greatly from person to person. Some people find that they have trouble falling asleep at night and can lie in bed for hours without being able to drift off. Others find that they fall asleep easily but wake many times during the night. Other people awaken too early in the morning and are then unable to get back to sleep. Some people even get enough hours of sleep but find that they do not feel rested, often because their sleep is too light.

Not all people experiencing insomnia have symptoms that occur during the daytime, but many do. Some people experience such symptoms as reduced ability to concentrate or pay attention, decreased alertness, and mental sluggishness. Some people have trouble staying awake. More people think that they have this symptom than actually do. Upon clinical examination many people who think that they are excessively sleepy during the day actually are not.

Many different things are thought to cause or contribute to insomnia. Such stressors as starting a new job or changes in routine, such as beginning to work a different shift, can lead to temporary sleep problems. Sleep problems can become aggravated, and persist after the worry or change causing the sleep problem has been resolved. This persistence is thought to be related to the anxiety created by attempting to go to sleep and not expecting to fall asleep. Anxiety about sleep loss can lead to a vicious circle in which the person has more and more concern about being able to fall asleep, making it ever increasingly difficult to do so. Some people even report that they are better able to fall asleep when they are not in their beds. This relative success is thought to occur because the new environment is not associated with the fear and anxiety of not being able to sleep, therefore making it easier to fall asleep.

Many other factors are thought to lead to or perpetuate insomnia. These include drinking tea or coffee, eating a large meal, taking certain medications or drugs of abuse (cocaine, amphetamines) that have a stimulating effect, or exercising heavily in the hours before attempting to sleep. Also, attempting to sleep in a room with too much light or noise can make it harder for some people to sleep. Doing activities in bed that are not associated with sleep, such as reading or watching television, can make it more difficult for some people to fall asleep when they finally want to. Sleep may be even more difficult if the television show or book was frightening or upsetting.