An estimated 20 to 40 percent of all adults complain about insomnia—a general term that refers to difficulty falling or staying asleep. Insomnia is not really a disorder but a symptom with many causes. For example, temporary insomnia can be caused by jet lag, which upsets the body’s biological clock, or by some specific, stressful situation like a divorce or change in job. Once these situations have been resolved, sleep returns to normal.

How alert and refreshed you feel, rather than how many hours of sleep you get, is a better sign of whether insomnia is a problem for you. Not everyone needs eight hours—the number often used as the benchmark for a good night’s sleep. Some people feel well rested after only six hours of sleep a night—though research suggests that others who think they are doing fine on five or six hours would actually benefit from more sleep.

Age is a key factor in assessing insomnia. It’s a sign of troubled sleep if a child or young adult has difficulty falling asleep or wakes up repeatedly. But in about 80 percent of people over the age of 60, sleep becomes more fragmented. People in this age group tend to wake up more often (and for longer periods) during the night, and earlier in the morning, with generally less deep sleep and more light sleep.

What Causes Insomnia?

Insomnia causes range from psychological and medical conditions to environmental factors like noise, light and room temperature. Medical problems linked to insomnia include

  • Depression
  • Allergies and colds
  • High blood pressure
  • Parkinson’s disease
  • Urinary frequency
  • Kidney failure
  • Stomach ulcers
  • Congestive heart failure (CHF)
  • Asthma
  • Other conditions
  • Insomnia can also be caused by specific sleep-related disorders, especially sleep apnea (a breathing malfunction that may interrupt sleep hundreds of times a night) and restless legs syndrome (an ailment marked by burning, prickling, and aching sensations in the legs at night).

    Many medications can also disturb sleep—both prescription and nonprescription drugs, including over-the-counter sleep aids that are used improperly. Consuming caffeine or alcohol and smoking at night to induce sleep are linked to sleep interruptions and waking up feeling unrefreshed.

    Many experts are convinced that in the majority of cases the original cause becomes secondary; instead, the insomnia persists because of behavioral factors that reinforce it, such as excessive time in bed, drug dependency, and napping. Also, the harder you try to fall asleep, the more anxious you become, which makes success all the more difficult.


    Talk to your health care provider about ways to prevent insomnia. Avoid taking sleeping pills. Not only can they produce daytime drowsiness and other side effects, but they lose their effectiveness if you take them every night.


    The Complete Home Wellness Handbook

    John Edward Swartzberg, M.D., F.A.C.P., Sheldon Margen, M.D., and the editors of the UC Berkeley Wellness Letter

    Updated by Remedy Health Media

    Publication Review By: the Editorial Staff at

    Published: 07 Nov 2011

    Last Modified: 23 Jan 2015