Sleep is an essential part of good health. A good night's sleep can help you feel good, look healthy, work effectively and think clearly.

But sleep is not always so easy to come by. If you sometimes have trouble falling asleep or staying asleep, you're not alone. A 1991 Gallup study found that more than one third of all Americans suffer occasional or chronic insomnia.

Insomnia is the sensation of daytime fatigue and impaired performance caused by insufficient sleep. In general, people with insomnia experience an inability to sleep despite being tired, a light, fitful sleep that leaves them fatigued upon awakening, or waking up too early. Under debate is the question of whether insomnia is always a symptom of some other physical or psychological condition or whether in some cases it is a primary disorder of its own.

People often are surprised to learn that daytime drowsiness is not an inevitable, harmless byproduct of modern life, but rather a key sign of a sleep problem that could be disastrous if not treated.

Recent figures show that nearly a quarter of the population regularly cannot go to, or remain asleep, and every year doctors write out more than 14 million prescriptions for sleeping tablets.

The worst part of insomnia is wanting to sleep but being unable to. The mind races and is unable to rest and that makes you overly tired and barely able to function the next day. Sometimes insomnia lasts longer than just a few nights.

Chronic insomnia may also be primary or secondary, depending on the cause: Primary chronic insomnia occurs when it is the sole complaint of a patient.Secondary chronic insomnia is caused by medical or psychiatric conditions, drugs, or emotional or psychiatric disorders.

There are several known causes for. It can be due to a medical condition, such as chronic pain from rheumatism or arthritis. It may be chemical, as a result of drinking tea, coffee or alcohol. Chronic or long-term insomnia is often associated with depression or anxiety, and environmental factors certainly contribute.

And sleepless nights, staring wild-eyed into the darkness, are worse than bad dreams,

For too many people - an estimated 9 percent of the American population - a good night's sleep is an elusive goal. The consequences of fatigue from chronic sleeplessness include accidents in the car and at work, a dramatically increased risk of major depression, and worsening physical illness.

Immediate relief is available, in the form of hypnotic agents, for persons who have difficulty in falling or remaining asleep or who cannot obtain restful, restorative slumber. However, long-term improvement usually involves behavioral therapy. These therapeutic approaches must be integrated if the patient's short- and long-term needs are to be addressed.