Insomnia

Insomnia (in-SOM-nee-a) is a disorder in which people have trouble sleeping or getting enough rest.

Humans, like all other living organisms, have cycles of activity and rest, which perhaps evolved partly as a response to the cycles of night and day. Many of the body's hormones * and processes are related closely to such daily cycles. Sleep provides the opportunity to rest, to restore certain essential neurotransmitters * , and even to avoid certain predators. Sleep, in short, is necessary to health and even to life.

Yet millions of people have insomnia. They may have difficulty falling asleep or staying asleep through the night, or they may wake up too early or sleep so restlessly that the body and mind are not refreshed. Insomnia is not defined by how long it takes to fall asleep or by how many hours a person sleeps, because these characteristics vary greatly from person to person. Babies may sleep 14 to 17 hours per day or more, and school-age children need between 9 and 11 hours every night. From young adulthood onward seven to nine hours are recommended, though some adults feel they function well with just three to four hours. People are diagnosed with insomnia when sleep problems begin to interfere with daily living, when they can no longer function normally during the day because they are tired or cranky, have no energy, and are unable to concentrate.

Everyone has trouble sleeping sometimes. Young people who are excited about a holiday or stressed about an exam might have trouble falling asleep. Adults who are worried about a sick relative or stressed at work might wake up in the middle of the night and not be able to fall back asleep. These are examples of transient (short-term) insomnia, which are sleep problems that last for one night or even for a few weeks and then disappear. In other cases, episodes of short-term insomnia come and go, which is called intermittent insomnia. But half of all people with insomnia have chronic * insomnia, which is a sleep problem that occurs on most nights for a month or longer.

Insomnia affects people of all ages, but it is most common in older people, especially women. When people travel, start a new job, or move to a new home or school, all of which are changes in routine, they can have trouble sleeping. Physical conditions such as pregnancy, arthritis, the need to urinate frequently, and leg cramps also seem to cause sleep problems. But the most common cause of insomnia is psychological * : anger, anxiety, depression * , and stress keep many people from sleeping well.

Good sleep hygiene refers to habits, routines, rituals, and practices that support relaxation and regular patterns of sleep.

Actions during the day and in the hours just prior to bedtime impact how easy it is to fall asleep, stay asleep, and get restful sleep.

Many over-thecounter (OTC) drugs are used for insomnia, most of which contain antihistamine, diphenhydramine, or doxylamine. Various problems attend using these drugs on a regular basis: drug tolerance * ; dependency (meaning a person comes to rely habitually on the drug to assure sleeping well); and various side effects, such as drowsiness the next day. These drugs can also cause problems for users who have certain existing conditions, for example, allergies, asthma, emphysema, chronic bronchitis, and glaucoma * . Most of these drugs should not be used during pregnancy. In addition to OTC drugs, certain herbs are believed to assist sleep, such as valerian. While some people may have allergic responses to herbs, other side effects are not associated with them. But even with herbal remedies, use should be as needed rather than habitual.

Prescription sleep medications are highly effective in treating insomnia, but they have disadvantages, chief among which may be physical and psychological dependency. These controlled substances can be abused and if abused can be dangerous and even life threatening. Prescription sleep medications may contain benzodiazepine (Restoril), eszopiclone (Lunesta), or zolpidem (Ambien). The second and third of these have reduced dependency risk.

For both OTC and prescription sleep aids, users should follow directions carefully, use only as needed rather than habitually, avoid alcohol consumption within several hours of taking the sleep aid, and inform any physician caring for the user of the drug's use. Sleep aids can be effective in special situations, such as in travel across time zones and following certain medical procedures. But they must be used with caution and care and only as needed.

See also Anxiety and Anxiety Disorders: Overview • Depressive Disorders: Overview • Jet Lag • Sleep Disorders: Overview

* neurotransmitters (nur-otrans-MIH-terz) are chemical substances that transmit nerve impulses, or messages, throughout the brain and nervous system and are involved in the control of thought, movement, and other body functions.

* hormones are chemical substances that are produced by various glands and sent into the bloodstream carrying messages that have certain effects on other parts of the body.

* chronic (KRAH-nik) means lasting a long time or recurring frequently.

* depression (de-PRESH-un) is a mental state characterized by feelings of sadness, despair, and discouragement.

* psychological (SI-ko-LOJ-i-kal) refers to mental processes, including thoughts, feelings, and emotions.

* glaucoma is a group of disorders that cause pressure to build in the eye, which may result in vision loss.

* tolerance (TALL-uh-runce) is a condition in which a person needs more of a drug to feel the original effects of the drug.