Insomnia is a sleep disorder that is characterized by sleeplessness, inadequate sleep, or poor quality sleep. 

The amount of sleep needed varies from person to person. In general, however, most people function best with seven or eight hours of sleep.

Insomnia can be a serious health and wellness concern because lack of sleep, especially good quality sleep, can affect your ability to function at work, in other daily activities, and in personal relationships.

Insomnia in Depth

Some people experience short-term insomnia, while others are affected for longer periods. Short-term insomnia that lasts for a few days or weeks is considered acuteinsomnia and is generally associated with a traumatic or stressful event. Chronicinsomnia, on the other hand, is longer-term issue, with sleep disturbances occurring at least three nights a week for a month or longer. Insomnia can also vary in severity—some cases are mild, whereas others are severe.

Some people develop habits as a result of insomnia or in response to drowsiness; these habits may worsen sleeplessness. They include taking naps, worrying about sleep, and going to bed early.

Who experiences insomnia?

Both men and women can experience insomnia, but it tends to affect more women than men. Possible explanations for the higher frequency among women include hormonal changes associated with the menstrual cycle and menopause; hormonal, physical, and emotional changes experienced during pregnancy; and a higher prevalence among women of medical conditions that can cause secondary insomnia (including depression, anxiety, and sleep disorders).

Risk factors for insomnia include: stress, depression, and emotional distress (such as divorce or death of a loved one), night work, travel with time changes, and an inactive lifestyle.

Types of Insomnia

Insomnia is divided into two types: primary insomnia and secondary insomnia.

Primary Insomnia

Primary insomnia is not a symptom or side effect of another medical condition but occurs independently of other illnesses, meaning that it is a condition of its own. Primary insomnia may affect an individual throughout life or may be triggered by stressful events, an unconventional work schedule (such as night work), travel, or other disruptive circumstances.

Secondary Insomnia

Unlike primary insomnia, secondary insomnia is a symptom or side effect of another health condition. Underlying medical causes of secondary insomnia include depression or anxiety, chronic pain, overactive thyroid, gastrointestinal problems, other sleep disorders (such as sleep apnea or restless leg syndrome), stroke, Alzheimer’s disease, or menopause.

Environment and lifestyle factors may also cause secondary insomnia. Examples of these factors include: certain medications (such as asthma, heart, allergy, and cold medicines); use of caffeine, tobacco, and alcohol; and poor sleep environment (a bedroom that’s too noisy or not dark enough, for example).

Secondary insomnia may go away once the issue causing sleeplessness is treated. In some cases, however, further treatment of insomnia itself is required.


Symptoms of insomnia include the following:

  • Lying awake for long periods with difficulty falling asleep
  • Waking up during the night and having trouble getting back to sleep
  • Waking up too early in the morning
  • Feeling like you haven’t slept at all

If you’re not sleeping well or enough, you may feel sleepy, have low energy, have trouble thinking clearly and staying focused, and feel irritable or depressed.


Your doctor can help you determine if you are experiencing insomnia. If you feel that you are having trouble sleeping, such as falling asleep or staying asleep, and that lack of sleep is affecting your daily activities, you may want to consult your doctor.

A sleep diary may help you and your doctor understand and treat insomnia. This diary should include a daily record of what time you fall asleep and wake up, any changes in your sleep and bedtime routines, and how you feel during the day. Also be prepared to tell your doctor about factors that may be affecting the quality of your sleep; these may include your bedtime routine, habits before bedtime (such as eating, drinking, watching TV), and bedroom environment (light, noise, temperature).

Sometimes a doctor will also recommend a physical exam and additional medical history to determine if other health conditions may be affecting sleep.

If you and your doctor aren’t able to identify a cause of your insomnia, your doctor may recommend a sleep study, or polysomnogram (PSG). A PSG usually requires an overnight stay at a sleep center. During your stay, a PSG records brain electrical activity, eye movements, heart rate, breathing, muscle activity, blood pressure, and blood oxygen levels. The goal is to diagnose an underlying sleep disorder that is causing your insomnia.