If you experience difficulty falling asleep, staying asleep, or enjoying a restful night's sleep, you may be suffering from insomnia. Insomnia is defined as the perception or complaint of inadequate or poor-quality sleep because of one or more of the following:

  • difficulty falling asleep
  • waking up frequently during the night with difficulty returning to sleep
  • waking up too early in the morning
  • non-refreshing sleep

Insomnia is a common symptom in the US. The Institute of Medicine estimates that between 50 and 70 million Americans have chronic sleep problems.

Insomnia is classified as:

  • Transient (short term) – lasting from a single night to a few weeks
  • Intermittent (on and off) – episodes occur from time to time
  • Chronic (constant) – occurs on most nights and lasts a month or more


Insomnia may be caused by many factors, including the following:

  • stress
  • depression
  • anxiety
  • physical illness
  • caffeine intake
  • irregular schedules
  • circadian rhythm disorders
  • drugs (including alcohol and nicotine)
  • occasional or chronic pain


Some of the symptoms of insomnia include:

  • daytime sleepiness
  • low energy or fatigue
  • anxiety or frustration about sleep
  • attention, concentration or memory problems
  • waking up tired or in pain