Half of all Americans have experienced insomnia, which can afflict its sufferers in a variety of ways.

Insomnia, or the inability to sleep, can take many forms.

Have you ever crawled into bed exhausted, thinking you'd fall asleep in seconds, only to find yourself still awake an hour later? Or maybe you tend to fall asleep quickly but wake up many times through the night. Or perhaps you wake up at 4 or 5 a.m. and can't get back to sleep, even though you still feel tired and don't have to get up until 7 a.m. These are all versions of insomnia.

If you can relate to any of these scenarios, you're in good company. Half of all Americans have experienced insomnia at some time in their lives, and a good number experience it on a regular basis.

Insomnia is a broad term that describes trouble going to sleep, staying asleep, or sleeping for the full time you need to in order to feel refreshed. Insomnia, like other secondary sleep disorders, is most often a symptom that some other physical, emotional, behavioral or environmental problem is affecting sleep. Most researchers characterize the different types of insomnia by frequency and length of time it continues. The following are the main forms of insomnia.

  • Transient, or temporary, insomnia typically lasts between one and several nights and is usually caused by stress or emotion.
  • Intermittent insomnia occurs off and on over a long period of time and is also most frequently a result of stress or anxiety.
  • Chronic insomnia occurs on most nights, lasts at least two weeks (and possibly much longer), and may result from one or more medical conditions.

Transient and intermittent insomnia are usually best treated by practicing some proven methods of stress reduction and/or changing your sleep environment. Chronic insomniacs may also need professional help, especially if their sleeplessness is related to a medical condition.There are several medical conditions -- heartburn, for example -- that can affect sleep. The link between heartburn and insomnia is discussed on the next page.For more information on how to get a good night's sleep, see: