Snooze University

10 Side Effects of Insomnia: Causes and Treatment

by Dale Cudmore | Updated: May 28, 2023

There are many potential negative side effects of insomnia.

The crazy thing is that insomnia itself is a side effect of another underlying issue.

I’ll summarize the 10 most common side effects of insomnia so that you can tell if sleep deprivation is causing your issues or not. I’ll also go over causes and treatment options if you’re struggling with getting to sleep.

10 Long-Term Side Effects of Insomnia and Sleep Deprivation

Not everyone with insomnia will experience all 10 of these side effects, so don’t panic. However, they do typically experience at least a few of them.

Furthermore, some of these symptoms will show up in the short term, while others are long term issues that can take years of sleep deprivation to develop.

Your specific symptoms and side effects will depend on the severity of your condition, type of insomnia, and individual factors based on your genetics.

Sleepiness and Fatigue

The most obvious side effect is that you’re going to be tired. Sometimes, people with insomnia experience microsleep, which is where you fall asleep for a short time (a few seconds to minutes) without even realizing it.

This can lead to accidents (particularly while driving) and mistakes at work. Chronic fatigue will also affect habits (like exercising), which can lead to further side effects.

More Stress and Worse Skin

Studies have shown that insomniacs have higher cortisol later on in the day (1). Cortisol is a hormone that is made in a response to stress.

If your cortisol levels stay elevated for a long period, there are all sorts of consequences. For one, it can break down collagen, which is a protein used in your body’s skin and connective tissue.

Chronic elevated cortisol can also reduce growth hormone production, which is needed to maintain muscle mass and bone density.

Lower Sex Drive

A study of over 1,000 men over 65 found that testosterone production corresponds to sleep duration (2):

Testosterone increased with increasing sleep duration up to 9.9 hours, after which it decreased

Chronic insomnia will lead to lower testosterone levels, which will lead to several consequences including a lower libido.

Another study restricted the sleep of 10 young men to see the effects. In just 1 week, serum testosterone significantly decreased (3):

It doesn’t take long for sleep deprivation to have negative consequences.

Weight Gain

There's a good amount of evidence that insomnia causes weight gain in most people.

If you’re tired, you’re going to move less. If you’re fatigued, you make poorer decisions, including eating decisions.

It’s reasonable to expect that sleep deprivation would cause weight gain.

That’s on top of issues like lower levels of growth hormone and testosterone.

And science supports this. Many studies have shown that people with insomnia are more likely to gain weight and become overweight (4).

Headaches and Concentration Problems

A study with 50 insomnia patients found that 48% of them experienced frequent headaches (5).

This is a side effect that I experienced personally on a daily basis back when I had sleep issues. Research shows that insomnia can cause headaches, and it's fairly common. That might prompt someone to take Tylenol that may make insomnia worse.

Additionally, people with insomnia score lower on tests relating to their concentration and focus levels. This will affect your work, and every other aspect of your life to a small degree.

Worse Memory

Primary insomnia (the main type) has been shown to affect memory.

Research has shown that sufficient sleep is needed to consolidate declarative memory (6). In other words, sleep helps you remember things clearly.

Mood Swings and Irritability

This is another side effect I can speak to myself.

When you have chronic insomnia, you’re constantly stressed (see note on cortisol earlier) and often have headaches. Even if you’re usually an emotionally stable person, this is going to affect your mood (7).

You’re going to be less patient, and more prone to becoming frustrated and annoyed, which will affect your happiness and relationships.

Emotional changes are one of the most common psychological effects of sleep deprivation, even in the short term.

Weakened Immune System (More Likely to Get Sick)

If you’ve ever wondered if you can get sick from insomnia, wonder no more: you absolutely can.

Again, research has shown that the cortisol levels in insomniacs significantly depress the immune system (8).

A weakened immune system can’t fight off disease as easily, which leaves you more vulnerable to getting sick.

Heart Problems (Long Term)

All of those side effects above start showing up in the short term, but some of them can lead to long term negative consequences as well.

There’s a clear association between insomnia and heart problems, diabetes, cardiovascular disease, and ischemic stroke (9).


A meta-study of 8 epidemiological studies found that (10):

...insomnia at baseline significantly predicted an increased depression risk at follow-up 1–3 years later.

Depression is seen in many insomniacs, and it also makes sleeping even harder, trapping people in a vicious cycle.

Causes of Insomnia

There are 6 main causes of insomnia (11):

  1. Side effect of other medication - Some treatments, particularly cancer treatments, cause insomnia as a side effect.
  2. Stress and Anxiety - While insomnia can raise stress levels, stress levels can also cause and make insomnia worse.
  3. Depression - People who are depressed often develop insomnia for a variety of reasons.
  4. Poor sleep hygiene - Having a poor sleeping environment can leave you sleep deprived. This includes things like temperature, blue light exposure, napping habits, and more. Here's my guide to good sleep hygiene.
  5. Hormones - Pregnancy insomnia is the most common type of insomnia that can be caused by changes in hormone levels.
  6. Substance abuse - Alcohol use and smoking can contribute to sleep issues, and are usually included in a separate category. Insomnia can persist even after quitting drinking, or quitting smoking.

Differences in Insomnia in Males Vs Females

For the most part, insomnia side effects are mostly the same regardless of whether you’re male or female.

However, insomnia caused by hormonal and stress issues are more likely in women. Men, on the other hand, are more likely to develop insomnia from lifestyle choices (e.g. alcohol, smoking, energy drinks) (12).

Medications That Cause Insomnia As a Side Effect

Many medications and treatments can cause insomnia, particularly antidepressants.

For example, up to 40% of prostate cancer patients develop insomnia as a result of their androgen deprivation therapy (13).

Here’s a list of the main different types of medications that may cause insomnia, along with a few popular brands of each (14):

  1. Alpha-blockers (e.g. Dibenzyline, Regitine, Prednisone, Alfuzosin) - Used for conditions like hypertension, Raynaud’s disease, and erectile dysfunction.
  2. Beta-blockers (e.g. Sectral, Tenormin, Zebeta) - Mainly used to protect the heart or to treat high blood pressure.
  3. Corticosteroids (e.g. Medrol, Deltasone, Sterapred) - Used to treat a wide variety of medical conditions because of their ability to reduce inflammation.
  4. Selective serotonin reuptake inhibitors, or SSRI (e.g. Zoloft, Celexa, Lexapro, Prozac) - Usually used as antidepressants.
  5. ACE inhibitors (e.g. Alacepril, Captopril, Zefnopril) - Used to treat high blood pressure and heart failure.
  6. ARBs (e.g. Valsartan, Telmisartan, Losartan) - Used to treat high blood pressure, kidney damage, and congestive heart failure.
  7. Cholinesterase inhibitors (e.g. Rivastigmine, Donepezil, Galantamine) - Helps treat Alzheimer’s disease and dementia.
  8. H1 antagonists (e.g. Clarinex, Allegra, Xyzal, Claritin) - Antihistamines used to treat allergies.
  9. Statins (e.g. Lipitor, Lescol, Mevacor) - Used to treat high cholesterol levels.

Insomnia Treatment Options

In less serious cases of insomnia, you can treat it at home. For acute insomnia (caused by temporary stress), you may not have to do anything special for it to clear up over time.

However, if it’s causing you obvious health problems, you should see a doctor who can conduct a sleep study on you to pinpoint your issues.

Treatment includes at least one of the following options in most cases:

  • Medication - Sleep medication is the “standard” treatment option, but often comes with other side effects (see next section). It can also take time to find a medication that works, and sometimes it stops working at some point in the future.
  • Cognitive Behavioral Therapy (CBT) - A relatively new treatment method for a variety of anxiety disorders, including insomnia. While more research is needed, it’s looking promising. It’s effective for most people, and has no negative side effects.
  • Acupuncture/Massage/Yoga - If insomnia is caused by stress, relaxation techniques and exercises can make a big difference. These are all supported by research.
  • Melatonin - If your insomnia is due to having to sleep at weird hours (common in shift work), simple taking a melatonin supplement may be enough.

A note on CBD for insomnia: I’ve seen it mentioned on a few forums as a potential solution. It might help, but it’s also completely unproven. There are some studies underway currently, but it will be many years before we have evidence either way.

Side Effects of Insomnia Medication

There are several types of insomnia medication.

The most common ones are progesterone, doxepin, and pycnogenol.

In many people, these cause unintended side effects:

  • Dizziness
  • Lightheadedness
  • Headaches
  • Gastrointestinal problems (nausea, diarrhea)
  • Drowsiness
  • Memory and concentration issues

It varies a lot on an individual level, but if you’re on a sleep medication, don’t be surprised if one of those above symptoms appears or gets worse.

What Happens if Insomnia is Not Treated?

Will insomnia kill you? Not directly, no.

There’s one condition called Fatal insomnia you can die from, but it is incredibly rare.

What insomnia does do is impact the quality of your life and potentially lead to the side effects we looked at before like heart disease.

Severe insomnia can also cause hallucinations.

Additionally, lack of sleep has plenty of short-term consequences. There's even evidence that a lack of sleep can make you feel colder.


  1. Recurrent short sleep, chronic insomnia symptoms and salivary cortisol
  2. Sleep Duration and Disturbances Were Associated With Testosterone Level, Muscle Mass, and Muscle Strength
  3. Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men
  4. The impact of obesity and weight gain on development of sleep problems in a population-based sample
  5. Headache characteristics in obstructive sleep apnea syndrome and insomnia
  6. Impaired Declarative Memory Consolidation During Sleep in Patients With Primary Insomnia
  7. Treatment of insomnia in patients with mood disorders
  8. Cancer pain, fatigue, distress, and insomnia in cancer patients
  9. Insomnia symptoms and risk of cardiovascular diseases among 0.5 million adults
  10. Primary insomnia: a risk factor to develop depression?
  11. Insomnia causes, consequences, and therapeutics: An overview
  12. Emergence of Sex Differences in Insomnia Symptoms in Adolescents: A Large-Scale School-Based Study
  13. Prostate cancer treatments and their side effects are associated with increased insomnia
  14. Drug-Induced Insomnia and Excessive Sleepiness

Medical Disclaimer: The information on is not intended to be a substitute for physician or other qualified care. We simply aim to inform people struggling with sleep issues about the nature of their condition and/or prescribed treatment.

About the authorDale is the founder of Snooze University and a sleep researcher. I overcame my sleep issues and now I'd like to help you do the same by summarizing the latest sleep studies for you.