What is insomnia?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

Insomnia is a common sleep disorder. If you ever have a hard time getting to sleep or staying asleep, you may have had short-term insomnia. Insomnia is called short-term when it happens fewer than three times a week, or if it happens for a period of less than a month. If it happens for more than that, it is known as chronic insomnia.

Insomnia can have a variety of causes. These include stress, anxiety, depression, a headache, or a weak bladder. Sometimes insomnia is caused by having too much caffeine, nicotine, alcohol, or food before bedtime. In some cases, starting or stopping a medication can interfere with sleep.

Nearly half of all Americans have trouble falling or staying asleep. The inability to get a good night’s sleep is called insomnia, and according to the National Sleep Foundation, 48 percent of Americans report having it at least once in a while. For 22 percent, insomnia is a nightly, or almost nightly, event.

Stacy Wiegman, PharmD
Pharmacy Specialist

Individuals suffering from insomnia have poor quality of sleep, difficulty falling and keeping asleep. Insomnia is usually caused by underlying conditions. Underlying conditions of insomnia may include psychological conditions, stress, environmental changes, and certain medications. It can also be provoked by abnormal daytime naps or caffeine consumption. Insomnia may also result from withdrawal from cocaine, amphetamines, benzodiazepines, antihistamines, alcohol and marijuana.

There are three different types of insomnia: transient, short-term, and chronic or long-term insomnia. Transient insomnia lasts for less than a week and results from environmental changes such as climate changes, jet lag, travel, and stress. Short-term insomnia lasts for one to three weeks and results from medication side effects, ongoing stress, and medical conditions. Chronic insomnia lasts for more than three weeks and results from substance abuse or depression.

Insomnia can be:
Transient (short term) insomnia lasts from a single night to a few weeks. Intermittent (on and off) insomnia is short term, which happens from time to time. Chronic (on-going) insomnia occurs at least 3 nights a week over a month or more.

Chronic insomnia is either primary or secondary:
Primary insomnia is not related to any other health problem. Secondary insomnia can be caused by a medical condition (such as cancer, asthma, or arthritis), drugs, stress or a mental health problem (such as depression), or a poor sleep environment (such as too much light or noise, or a bed partner who snores).

This information is based on source information from the National Women's Health Information Center.

Dr. Michael Breus, PhD
Psychology Specialist

Insomnia is often referred to as “vague” because it is so difficult to determine what exactly is causing the sleeplessness: underlying medical conditions, chronic pain, depression, or even another sleep disorder like restless leg syndrome. For some, the cause could be as simple as stress.

Regardless of the cause, all insomniacs know that it can be nearly impossible to fall asleep or fall back to sleep. If you have insomnia, you may spend hours lying in bed, tossing and turning, trying desperately to fall asleep. You may even feel that doing so makes you feel even more stressed about not being asleep. A new study suggests that not only is that stress keeping you awake, being in the bed itself might be contributing to your sleeplessness.

Insomnia is a disorder marked by a lack of sleep or poor-quality sleep. It may be acute or chronic.

The latest studies indicate that nearly a quarter of the American population suffers with insomnia almost every night.

Although anyone can experience insomnia at any time, it is more common in women, and it tends to increase with age. It often, though not always, occurs in conjunction with other health problems.

Insomnia can be short-term or chronic. Short-term insomnia lasts for up to 3 months. Chronic insomnia occurs at least 3 times a week and lasts for at least 3 months.

This content originally appeared on the American Academy of Sleep Medicine website.

Insomnia is a common condition in which you have trouble falling asleep, staying asleep, or returning to sleep after you awaken. It can be a chronic (long-term) problem if it lasts more than 3 nights per week for more than a month. Or it may be an acute (short-term) problem if it lasts less than that. Either way, it can be very disruptive to your daily routine. Most people (8 out of 10) have insomnia that is caused by a medical condition, medicines, or other substances.

Insomnia is more than just a nuisance that may leave you feeling tired the next day. If it is a chronic problem, it may raise your risk for heart attack and stroke. Research studies have shown a link between fewer than 6 hours of sleep a night and cardiovascular disease. If you have long-term insomnia, your physician can help you identify and treat the cause.

Dr. Mehmet Oz, MD
Cardiologist (Heart Specialist)

At some point, we've all experienced at least a few nights of too little or restless sleep. Many of us are familiar with the consequences of one or more sleepless nights such as sluggishness, poor concentration, irritability, and changes in appetite. For the majority of cases, it takes just a day or two to catch up on restorative sleep. Yet for up to half of the population, lack of sleep can turn into a more serious problem: insomnia.

There are two types of insomnia: primary insomnia and secondary insomnia. Primary insomnia is triggered by travel, stress, shift work—anything that disrupts sleep. Secondary insomnia, which is the most common type of insomnia, is a symptom or a side effect of something else, like illness, stress, anxiety, hormonal imbalance, or depression.

While experts may disagree over the exact definition, insomnia is typically characterized by the duration of symptoms, not the specific amount of sleep one gets. Individuals may have vastly different sleep practices and require different amounts of sleep, but true insomnia usually involves difficulty initiating or maintaining sleep for at least one week or more.

Even more troublesome, the causes of insomnia remain a mystery for many sufferers. It's not a disease in and of itself—it's a symptom of another underlying problem. Therefore, the key to treating insomnia involves unearthing the root cause.


Insomnia, the most common sleep disorder, is defined as difficulty falling asleep or difficulty maintaining sleep every night or most nights, despite an adequate opportunity to sleep. Other symptoms of insomnia include waking too early in the morning and being unable to fall back to sleep and experiencing an unrefreshing night's sleep. As a result of a poor night's sleep, you typically feel tired and irritable the next day and have trouble concentrating on everyday tasks.

The key to accurately diagnosing insomnia is talking with your healthcare professional about your overall health. If you experience chronic insomnia (insomnia occurs most nights and lasts one month or more), one or more of the following conditions may be the cause:

  • medical, emotional and psychological problems
  • depression, anxiety and emotional crises such as a death, illness, divorce or other stressful events
  • physical conditions such as arthritis, kidney disease, heart failure, heartburn, asthma, Parkinson's disease and hyperthyroidism
  • circadian rhythm disruptions such as shift work
  • prescription or nonprescription medications
  • stimulants such as caffeine and nicotine
  • alcohol and other drugs
  • other specific sleep disorders such as restless legs syndrome (RLS) or sleep apnea

Intermittent and transient insomnia (insomnia that lasts only for a few nights and returns from time to time) can result from:

  • temporary changes in the surrounding environment
  • stress
  • extreme temperatures
  • circadian rhythm disruptions such as jet lag
  • side effects from medication taken on a short-term basis

Insomnia is a problem getting to sleep, staying asleep or feeling rested by sleep. It is a symptom rather than a disease. In fact, it is a symptom most everyone is likely to have some nights, often because of happy events like weddings or other special occasions, or because of stressful events like divorce or health problems. If the problem lasts for more than a few nights and the person has trouble functioning during the day because of it, then it is worth seeking help. Insomnia is treatable.

Insomnia is usually caused by more than one factor working together over time. For example, people who have a death in the family often have several sleepless nights immediately following the death. In reaction to their poor sleep, they may start taking sleeping pills at night and drinking more caffeine during the day. They may also spend more hours in bed at night in hopes they will sleep a little more. In this case, the insomnia is caused by more than one factor: the stress, the sleeping pills, the caffeine, and too much time in bed.

Mood problems like depression (feeling sad) or mania (feeling elated) and anxiety problems may worsen insomnia. Although people with these problems may think their mood will improve if their sleep gets better, it usually works better to treat the mood or anxiety problem first.

Another factor that increases the risk of insomnia in some people is an irregular schedule of getting to sleep and waking up. Good examples are policemen and nurses and others who do shift work. The brain has its own internal clock or time keeper that directs the body in its daily rhythms of sleeping and waking. If a person goes to sleep and wakes up at different times on different days, the time of day he or she needs to sleep or wake up on any given day may not be the time of day that the brain thinks the body should sleep or wake up.

Insomnia can be caused by prescription medication or by street drugs. When you begin a medication, ask whether it is likely to interfere with sleep or cause tiredness during the day. Cocaine and related drugs can interfere with sleep. Nicotine may also affect sleep.

Some people use alcohol as a sleep aid. This is a mistake since alcohol disturbs the normal stages of sleep. Many people who drink alcohol in the evening find they wake up in the middle of the night and have trouble getting back to sleep.

Caffeine in coffee, tea and some soft drinks can also affect sleep. Too much caffeine can make it hard to fall asleep.

Chronic pain can cause insomnia, as can a problem called Restless Leg Syndrome.

In general, there are seven types of insomnia that are generally characterized as having difficulty with falling asleep, waking often with difficulty falling back asleep, waking up too early in the morning, and/or feeling tired when waking. 

  1. Adjustment insomnia is usually related to a source of stress that lasts for only a few days to weeks.
  2. Behavioral insomnia of childhood is insomnia that affects children and occurs in two types, including sleep-onset association type and limit-setting type. Sleep-onset type is where a child is used to an action with bedtime such as a bottle, rocking, or going to the parents' bed before bedtime, and if that association is removed, he/she has difficulty with going to sleep. Limit-setting type occurs when a child refuses to sleep due to absence of strictly enforced bedtime limits.
  3. Idiopathic insomnia is a lifelong insomnia that cannot be explained by other medical conditions or causes.
  4. Inadequate sleep hygiene is an insomnia associated with a bad habit such as watching TV in bed or frequent naps during the day.
  5. Insomnia due to drug, substance, medical condition, or mental disorder is associated with medical conditions/substances and is most commonly associated with depression or another psychiatric disorder.
  6. Paradoxical insomnia is the complaint of severe insomnia without objective evidence of a sleep disturbance.
  7. Finally, psychophysiological insomnia is insomnia associated with an excessive amount of anxiety and worry regarding sleep and sleeplessness.
Boston Women's Health Book Collective
Administration Specialist

Most of us need between seven and nine hours of sleep a night to function at our best, although some people feel alert and rested after fewer hours. Insomnia is the inability to obtain adequate sleep. People experience insomnia in a variety of ways, including having difficulty falling or staying asleep, waking too early in the morning, and waking up feeling unrefreshed. Almost everyone experiences occasional bouts of insomnia. If your sleep is disrupted for three or more nights a week for more than one month at a time, you have what is considered chronic insomnia. Chronic insomnia often causes problems during the day, such as sleepiness, fatigue, difficulty concentrating, and irritability. It can contribute to poor performance on the job and car accidents, and profoundly affect your sense of well-being and general health.

Our Bodies, Ourselves: Menopause

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.