Insomnia

Insomnia means you have trouble falling asleep, staying asleep, or getting good sleep, even when you have enough time and a good place to sleep. It also affects your days. You may feel tired, cranky or foggy.^1,6

Almost everyone has a bad night now and then. But for some people, poor sleep goes on for months. The good news is that long-term insomnia can be treated, and the best-tested treatment does not need a pill. This page explains what insomnia is, why it sticks around, and what helps.

What counts as insomnia?

Insomnia can show up in a few ways. You may lie awake a long time before you fall asleep. You may wake up often during the night. Or you may wake too early and not get back to sleep.³

Trouble falling asleep is more common in younger adults. Waking often during the night is the most common problem, and it mostly affects older adults.³

Insomnia is not only about the night. Common daytime effects include:^3,6

• Waking up unrefreshed, or feeling sleepy or low on energy during the day
• Trouble paying attention, focusing or remembering
• Feeling irritable, anxious or down
• Making more mistakes at work or while doing tasks
• Worrying about sleep itself

Short-term and chronic insomnia

Doctors also check that the sleep trouble is not fully explained by another health problem.¹ For example, loud snoring and waking up gasping can point to sleep apnea, a different sleep disorder.⁴

How common is it?

Up to about 1 in 3 adults (35%) report some insomnia. At any one time, about 15% to 20% of people have short-term insomnia. About 1 in 10 adults has the chronic kind.⁶

The chance of insomnia goes up with age. It is also more common in women. Hormone changes in pregnancy and menopause can disturb sleep.²

What causes insomnia?

Insomnia usually has more than one cause. Common ones include:^2,6

• Stress and worry: work, money, relationships, a death or a divorce
• Mental health conditions: especially depression and anxiety. See Sleep, mood and anxiety.
• Health problems: pain, trouble moving, menopause, and other sleep disorders such as restless legs syndrome
• Medicines and substances: some cold and allergy medicines, some antidepressants, caffeine, nicotine and alcohol
• Your surroundings: noise, light, a room that is too hot or cold, or a bed partner who snores
• Schedule and habits: night or rotating shifts, travel across time zones, an irregular sleep schedule, long naps, too little daytime activity, and screens close to bedtime

Insomnia can also run in families.²

In later life. Many older adults have long-term health problems, so insomnia linked to medical conditions is most common in this group.⁶ Older adults still need about 7 to 9 hours of sleep a night, like younger adults.¹³ Read more in Sleep in later life.

Why insomnia keeps going: the "3P" model

Sleep experts often explain chronic insomnia with a simple idea called the 3P model. It was first described by sleep researcher Arthur Spielman. It names three kinds of factors that work together:⁷

1. Predisposing factors (things that make you more likely to get insomnia). These are part of who you are, such as being a light sleeper, a worrier, or someone whose sleep is easily upset by stress.
2. Precipitating factors (triggers). Something happens, such as an illness, a loss, a move or a hard time at work. It pushes your sleep past a tipping point, and the insomnia starts.
3. Perpetuating factors (things that keep it going). These are habits, thoughts and learned links that build up over time. They keep insomnia going even after the trigger has passed.

The third "P" is the key to treatment. You often cannot change your nature, and the trigger may be long over. But you can change the things that keep insomnia going.^7,9

Common habits and thoughts that keep insomnia going

When sleep goes badly, it makes sense to try to "catch up." But some natural fixes can backfire:

• Spending more time in bed. Going to bed early or sleeping in can spread a small amount of sleep over a long night. Sleep becomes light and broken. CBT-I limits time in bed for a while to build up a stronger drive to sleep.⁹
• Lying in bed awake. Over time, the bed starts to feel like a place for being awake, tossing and worrying. CBT-I works to break that link.⁹
• Long daytime naps. Big naps can take the edge off your sleep drive at night.^2,9
• Worrying about sleep. Watching the clock and fearing the next day can make you more alert at bedtime.²

Quiet, lonely time awake in bed can also turn into a time for going over problems again and again. That replaying, called rumination, can then feed more poor sleep.¹¹ Research also suggests that a stretch of insomnia can make a person's sleep more easily upset by stress later on.¹¹

In one study, researchers followed people who had just started having insomnia. After a month, those who were more likely to still have it had insomnia before, had more symptoms of depression, or felt very upset and preoccupied about their sleep.⁷ This is one reason it can help to get support early.

Is insomnia harmful?

Insomnia can affect your memory and focus. Over time, chronic insomnia is linked to a higher risk of high blood pressure, heart disease, diabetes and some cancers.¹ Insomnia and low mood often go together, and each can make the other worse.^3,11 See Sleep, mood and anxiety.

These links do not mean one bad week will harm your health. They are a reason to take long-lasting insomnia seriously and get help.

How is insomnia diagnosed?

There is no single test for insomnia. A doctor diagnoses it mostly by talking with you.⁴ It helps to keep a sleep diary for 1 to 2 weeks before your visit. Write down when you go to bed, when you get up, naps, how sleepy you feel during the day, caffeine, alcohol and exercise.⁴ Our sleep diary lesson shows you how.

Your doctor may ask about:⁴

• How often you have trouble sleeping and how long it has gone on
• Your bed and wake times on workdays and days off
• Snoring, or waking up gasping or choking
• Your other health problems, medicines, and use of caffeine, nicotine, alcohol or drugs

Your doctor may order blood tests to check for thyroid problems or other conditions. A sleep study may be needed if the doctor thinks you could have another sleep disorder, such as sleep apnea.^4,6

What helps: CBT-I first

Cognitive behavioral therapy for insomnia (CBT-I) is a short, structured program that changes the habits and thoughts that keep insomnia going.^5,9

In 2016, the American College of Physicians (ACP) said all adults with chronic insomnia should get CBT-I as their first treatment. It called this a strong recommendation based on moderate-quality evidence.⁸ In 2021, the American Academy of Sleep Medicine also gave CBT-I a strong recommendation.⁹

What CBT-I includes

CBT-I usually combines these parts:^5,9

• Sleep restriction (a set "sleep window"): for a while, you spend only about as much time in bed as you actually sleep. Then the window grows as your sleep gets deeper and steadier.
• Stimulus control: you go to bed only when sleepy, get up if you cannot sleep, keep the same wake time every day, and use the bed only for sleep and sex.
• Cognitive therapy: you learn to notice and calm worried thoughts about sleep.
• Relaxation: breathing, muscle relaxation or meditation to quiet body and mind.
• Sleep education: how sleep works and which habits help.

Try our free CBT-I lessons

Our five lessons walk you through the main steps of CBT-I:

1. The sleep diary
2. Setting your sleep window
3. Retraining your bed for sleep
4. Calming thoughts about sleep
5. Wind-down and staying on track

For the relaxation part, you can also try muscle relaxation, a body scan or box breathing.

What about sleep medicines?

If CBT-I alone does not help enough, the ACP suggests you and your doctor decide together whether to add a medicine for a short time. You would weigh the benefits, harms and costs.⁸

Sleep medicines can cause problems. These include getting used to the medicine so it works less well, doing things while not fully awake (such as walking or driving), falls, and memory problems. They should be used only with a doctor's care.⁶ Over-the-counter sleep aids that contain antihistamines can be unsafe for some people. Research has not proven that melatonin works for insomnia.⁵

Talk with your doctor or pharmacist before starting, stopping or changing any sleep medicine or supplement. Our page Sleep medicines: what to know covers each type in detail.

When to get help

Talk with your doctor if:

• Your sleep trouble has gone on for 3 months or more. That is when a sleep doctor's checkup is advised.⁶
• Poor sleep is hurting your work, mood, safety or relationships.
• You or your bed partner notice loud snoring, pauses in breathing, or gasping. These can be signs of sleep apnea.⁴
• You think a medicine, pain or another health problem is keeping you awake.
• You nod off while driving or during daily tasks.

You can also start with our check-in or the Sleep and insomnia overview.

Education only. This page is general information written from the sources listed. It is not medical, legal or financial advice and does not replace a doctor, therapist or lawyer who knows your situation. How we write and check pages.