What Is Primary Insomnia?

Table of Contents
View All
Table of Contents

Primary insomnia is a condition characterized by difficulty sleeping. Unlike secondary insomnia, primary insomnia isn’t the result of medication side effects or medical or psychological problems. The sleeplessness caused by primary insomnia can be frustrating for you at bedtime, and you can end up feeling tired or irritable throughout the day.

Man in bed looking at clock
Cavan Images / Getty Images

Primary insomnia is fairly common, and sometimes it can resolve without treatment. But if you are having persistent insomnia, you may need a diagnostic evaluation, including blood tests or an overnight sleep study to determine whether there is an underlying cause.

Managing lifestyle habits is usually effective for the relief of primary insomnia. If that doesn’t work, medical treatment might be necessary. 

Primary Insomnia Symptoms

Primary insomnia often means not getting enough sleep. People who have primary insomnia average six hours of sleep per night, while people who don't have the condition average about eight hours of sleep per night. You might notice that you toss and turn at night or get up out of bed frequently.

Typically, primary insomnia makes it hard to fall asleep and/or stay asleep. You might wake up easily during the night due to triggers like noises, or even without a trigger.

Sleep deprivation can lead to a number of effects during waking hours. Symptoms of insomnia-associated fatigue include:

  • Trouble waking up in the morning
  • Feeling tired and sleepy during the day
  • Hypersomnia (sleeping during the day)
  • Lack of motivation
  • Yawning 
  • Difficulty concentrating 
  • Hunger 
  • Headaches 
  • Sensitivity to noise or lights when awake
  • Lack of energy for physical activity, like exercise 
  • Irritability 
  • Jumpiness and being easily alarmed or frightened 
  • Unfocused hyperactivity 

You might have these symptoms for a few days in a row, and they can resolve the day after a restful night of sleep or after a nap. Sometimes fatigue can actually lead to falling asleep, with resolution of insomnia. 


You can develop a lot of anxiety and distress about the fact that you aren’t sleeping. This anxiety is usually more severe at bedtime or in the middle of the night, but you might notice that you worry about your insomnia during the day too. 

Over time, persistent insomnia and chronic lack of sleep can lead to depression and may predispose you to health complications. Not getting enough sleep is associated with lowered immune system function, obesity, and heart disease.


The key feature of primary insomnia is that it doesn’t have an identifiable cause. But there may be some risk factors that predispose you to have primary insomnia.

The condition tends to persist throughout a person’s life, often worsening or improving for months or years at a time. So, you might recall having trouble sleeping for many years. And primary insomnia can be more common among people who have family members with insomnia.

Research also suggests that, while primary insomnia isn’t caused by psychiatric issues, having a tendency to ruminate or a worry-prone personality might be predisposing factors.

Circadian Rhythm Pattern

Research shows that primary insomnia is associated with circadian rhythm irregularities. Primary insomnia may result in a pattern of falling into deeper phases of sleep earlier in the night than what is normally observed in people who don’t have the condition.

But it is hard to know whether that early deep sleep pattern is actually a cause or an effect of primary insomnia—because sleep deprivation also leads to the abrupt or rapid onset of deep sleep. 


Getting enough sleep is a common concern that many people have throughout life. A diagnosis of primary insomnia includes several steps.

One of the main components of identifying insomnia is determining whether you actually need more sleep than you are getting. If you aren’t able to sleep as much as you need to, then the second aspect of primary insomnia diagnosis is focused on finding the reason for your lack of sleep. 

The difference between primary insomnia and secondary insomnia is primary insomnia doesn’t have a medical or emotional cause, while secondary insomnia does.

Diagnostic tests can include tests that measure insomnia and its effects. These tests include:

  • Sleep study: A polysomnogram is an overnight sleep study that includes measures of brain activity, muscle activity, and breathing. With primary insomnia, the polysomnogram would be expected to show a decreased amount of sleep and a normal breathing pattern.
  • Pittsburgh sleep quality index (PSQI): This is a questionnaire that includes a self-assessment of sleep. It can help in identifying sleep patterns, as well as issues like getting up frequently at night to use the toilet.
  • Multiple sleep latency test (MSLT): An MSLT is a daytime nap study, in which you would be monitored during the day to see how quickly you fall asleep. The test results are a reflection of your sleep deprivation.

All of these sleep studies are used to help assess whether you are not getting enough sleep and what type of sleep interruption you are experiencing. 

Other tests you might need include screening questionnaires or other assessments of emotional issues like depression and anxiety. Sometimes, people are aware of these problems, but many people brush off symptoms of depression and anxiety—and they can manifest as insomnia instead. 

Ruling Out Underlying Causes of Insomnia

Medical causes of insomnia can include thyroid disease, liver disease, dementia, restless leg syndrome, and breathing problems. You might need to have tests to determine whether you have any of these underlying issues contributing to your insomnia. Your diagnostic testing would be guided by your medical symptoms and physical examination.


Sometimes mild cases of primary insomnia improve after a few days. Being really exhausted can make you sleepy, and you might end up falling asleep and getting enough rest.

But often, the sleepiness doesn’t happen when you want it to, and you can end up falling asleep during the day—and then again having trouble sleeping at night when you want to sleep. If the pattern of napping during the day doesn’t work well for you, then you need to make some changes to help alleviate your insomnia. 

Sleep Habits

You can make some lifestyle adjustments to help regulate your sleep. The key is to avoid things that prevent you from falling asleep when you want to.

Habits to consider include:

  • Avoiding caffeine in the afternoon or evening 
  • Avoiding alcohol
  • Not looking at your phone, computer, or television screens in the evening 
  • Staying away from bright lights for several hours before you want to fall asleep 
  • Scheduling your tasks so you feel that you are caught up before you plan to go to sleep 
  • Getting enough to eat so you aren’t hungry before you want to sleep 
  • Not eating so much that you feel bloated before you want to sleep 
  • Doing some light exercise several hours before you want to sleep 
  • Not napping during the day

Medical Treatment 

If lifestyle habits don’t help alleviate your insomnia, you can talk to your healthcare provider about medical therapy. Your healthcare provider might recommend that you try melatonin, or may prescribe medication such as antidepressants, antihistamines, or benzodiazepines.

Usually, it is not considered ideal to take prescription medication for insomnia for longer than a few weeks. These medications can have side effects, and the benefits might not be long-lasting.

Some people notice a benefit from treatment with non-prescription based strategies like counseling, cognitive behavioral therapy, or acupuncture. These approaches might have a longer-lasting effect, without the risk of side effects.

A Word From Verywell

Insomnia affects most adults at some time or the other. A diagnosis of primary insomnia means that you don’t need to worry that your sleep problems are caused by a medical issue. Sometimes insomnia is short-lived, but it can recur later in life. If you have had resolution of your insomnia before, there’s a good chance it will improve with treatment if it recurs.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Flynn-Evans EE, Shekleton JA, Miller B, et al. Circadian phase and phase angle disorders in primary insomnia. Sleep. 2017;40(12):10.1093/sleep/zsx163. doi:10.1093/sleep/zsx163

  2. Salisbury-Afshar E. Management of insomnia disorder in adults. Am Fam Physician. 2018;98(5):319-322.

  3. Sun Q, Tan L. Comparing primary insomnia to the insomnia occurring in major depression and general anxiety disorder. Psychiatry Res. 2019;282:112514. doi:10.1016/j.psychres.2019.112514

  4. Hung CM, Li YC, Chen HJ, et al. Risk of dementia in patients with primary insomnia: a nationwide population-based case-control study. BMC Psychiatry. 2018;18(1):38. doi:10.1186/s12888-018-1623-0

  5. Guo HM, Liu M, Xiang YT, et al. Insomnia in adults with chronic hepatitis B, liver failure, and cirrhosis: A case-control study. Perspect Psychiatr Care. 2017;53(1):67-72. doi:10.1111/ppc.12138

By Heidi Moawad, MD
Heidi Moawad is a neurologist and expert in the field of brain health and neurological disorders. Dr. Moawad regularly writes and edits health and career content for medical books and publications.