Insomnia is defined as inadequate or poor-quality sleep despite having adequate time to sleep. Insomnia may take the form of difficulty falling asleep, or middle-of-the-night or early-morning awakening. It may be a short-term problem or occur more often over a long period of time.

Over the course of a year, about one third of adults experience some level of insomnia. About 10%-15% have more severe or chronic insomnia. It may cause problems during the day, such as tiredness, a lack of energy, difficulty concentrating, and irritability.

Insomnia is not a disease. Instead, it is a result of a behavior or a symptom of an underlying mental or physical problem. There are many causes of insomnia.

Short-term insomnia is often due to temporary situations. It generally occurs in people who are experiencing one or more of the following:

    
  • A life crisis or stress
  • A change in the sleep environment, including factors such as noise, light, or temperature
  • Sleep/wake schedule problems, such as those due to jet lag or temporary shift work
  • Side effects of medication
  • Chronic insomnia often results from a medical condition. They may include:

        
  • Depression
  • Anxiety
  • Arthritis
  • Manic disorders
  • Stress in relationships
  • Conditions that cause chronic pain
  • Kidney disease
  • Heart failure
  • Asthma
  • Sleep apnea
  • Narcolepsy
  • Restless legs syndrome
  • Parkinsons disease
  • Dementia or Alzheimers disease
  • Hyperthyroidism
  • Gastroesophageal reflux disease
  • Pregnancy
  • Menopause
  • Sickle cell disease
  • Chronic insomnia may also be due to behavioral factors. These include:

        
  • Misuse of nicotine , caffeine , alcohol , or other substances
  • Disrupted sleep/wake cycles from shift work or other nighttime activity schedules
  • Chronic stress
  • For some people, insomnia is aggravated by:

        
  • Expecting to have difficulty sleeping and worrying about it
  • Excessive napping in the afternoon or evening