What Is Insomnia?

Reviewed by: HU Medical Review Board | Last reviewed: June 2020

Insomnia means a person has trouble falling asleep or staying asleep. Short-term, or acute, insomnia usually lasts for a few days or weeks. Chronic insomnia occurs at least 3 times a week for 3 months or longer.1

Who gets insomnia?

Short-term insomnia affects 30 to 50 percent of people at some time in their lives. Chronic insomnia affects between 5 and 10 percent of people. Insomnia is more common in people with certain physical and mental health conditions.2

Women are more likely to experience both short- and long-term insomnia than men. Long-term insomnia occurs most often in women, older adults, and those with severe insomnia.1,2

What causes insomnia?

Short-term insomnia can result from any type of stress such as pain, job loss, death of a loved one, divorce, or worry. Changes in routine may also cause insomnia. Insomnia usually improves once the stress has passed or the body has adjusted to the new routine. However, short-term insomnia can become a long-term problem if poor sleep habits develop during this time.1,2

Chronic insomnia may come and go from night-to-night over years, depending on stress and overall health.1,2

Types of long-term (chronic) insomnia

Chronic insomnia is divided into 2 types: primary and secondary. Primary insomnia is insomnia with no known cause. Most people with chronic insomnia have secondary insomnia. Secondary insomnia is caused by some other health issues.3

Among the many health conditions that may cause secondary insomnia are:3

  • Mental health issues such as depression, anxiety, or post-traumatic stress disorder (PTSD)
  • Brain injury
  • Brain disorders such as stroke, Alzheimer’s, or Parkinson’s disease
  • Asthma and other lung disease
  • Pregnancy
  • Menopause, most often due to symptoms such as hot flashes
  • Cancer
  • Sleep apnea
  • Restless legs syndrome
  • Side effects of drugs
  • Thyroid problems
  • Chronic pain

What are the symptoms of insomnia?

The lack of good sleep impacts daily life in many ways. Some symptoms of insomnia include:1

  • Fatigue or low energy
  • Difficulty concentrating
  • Mood changes such as being irritable, aggressive, impulsive, or hyperactive
  • Performance problems at work or school
  • More mistakes or accidents
  • Worry about sleep

How is insomnia diagnosed?

A sleep diary will help your doctor diagnose your sleep problem. You should record details of your sleep each day for at least 1 to 2 weeks. It will be helpful for your doctor to know:

  • How long it takes you to fall asleep
  • How long you stay asleep
  • When you wake up each day
  • How many naps you take and for how long
  • Your symptoms such as daytime sleepiness, fatigue, moods
  • Caffeine intake
  • Alcohol usage
  • If you have trouble turning off your thoughts at night
  • Your exercise routine

Be prepared to talk about how long you have experienced insomnia and what your sleep environment is like. Light, noise, room temperature, bedding, lack of exercise, smoking, and eating or drinking alcohol before bedtime can all cause sleep problems.

Your doctor may also ask you to fill out a 1-page survey called the Insomnia Severity Index, or ISI. This quick test gives your doctor an idea of how severe your insomnia may be.4

How is insomnia treated?

Treatment for insomnia depends on the root causes of the sleep problems. People with an underlying health issue, such as depression, chronic pain, or sleep apnea, may need to be treated for that medical condition to see their insomnia improve. Certain drugs, including stimulants, certain antidepressants, steroids, and opioids, can cause insomnia. Lowering the dose or changing to another type of drug may help relieve the insomnia.5

Changing sleep habits may bring relief, especially for those with short-term, or acute insomnia. Going to bed and waking up at a consistent time each day (including weekends) may help some. Others may need to reduce light, noise, and electronic distractions in the bedroom.5

Chronic, or long-term, insomnia may benefit from improved sleep habits. More often, chronic insomnia requires cognitive behavioral therapy (CBT-I) and drugs.  There is a cooling device worn on the forehead at night that has also been FDA-cleared for insomnia. Your doctor can help you determine which option would be best for you.5

Other types of sleep disorders

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