Why Can’t I Sleep? Surprising Causes of Insomnia

03/29/2021 | 6 min. read

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Nothing is more frustrating than lying in bed at night, hoping and praying you’ll fall asleep when it just isn’t happening. 

You know all the “tricks.” You’ve laid off coffee late in the day because you know caffeine’s effects on sleep. Your bedroom is cool, dark, and free of electronic devices. You’ve taken your bedtime dose of melatonin, plus GABA and L-theanine to calm and relax you. Yet sleep remains elusive. 

I have written in detail about these and other proven methods for overcoming insomnia, but if you are still struggling despite doing all the right stuff, it’s time to dig deeper and explore other potential causes of sleep problems. 

Rule Out Sleep Disorders 

You would think specific sleep disorders would be the first consideration, but these common problems are often overlooked:  

  • Sleep apnea: Insomnia is an obvious consequence of sleep apnea. This condition affects 10–15% of Americans, but the majority have never been diagnosed or treated. If you snore, are obese, or experience daytime sleepiness, talk to your doctor about testing and treatment.
  • Restless leg syndrome: Some three million Americans experience this unpleasant and uncontrollable urge to move their legs while at rest. In addition to making it hard to fall asleep, restless leg syndrome during sleep can wake you up and mess with your sleep cycles. Treatable causes include iron deficiency and neuropathy.
  • Circadian rhythm disorders: Jet lag, night-shift work, inadequate light exposure during the day, and too much light at night (especially blue light from electronic devices) can throw off your body clock. Honoring nature’s light-dark cycles, a regular bedtime, and supplemental melatonin help to reset your circadian rhythm.

Emotions, Stress & Insomnia 

Stress and emotions are a huge contributor to insomnia. When you’re worried, nervous, or stressed out, your adrenal glands release hormones that speed up your heartbeat, raise your blood pressure, tense your muscles, and make you more alert—not a good thing when you’re trying to sleep. 

Anxiety is often accompanied by sleep complaints. Depression causes insomnia as well and can interfere with both falling asleep and staying asleep. Sleeping pills and medications for anxiety or depression are not always the answer. Instead, explore natural techniques for managing stress such as exercise, acupuncture, and supplements that help blunt the stress response. 

Can Nutritional Deficiencies Cause Insomnia? 

I have been asked about links between specific nutrients and sleep. For example, does vitamin D deficiency cause insomnia? What about magnesium deficiency and sleep? 

Vitamins and minerals play a key role in all aspects of physiological function, so a deficiency in any essential nutrient could certainly have an adverse effect on your sleep. That is one of many reasons why I recommend that everyone take a good daily multivitamin and mineral supplement. Specific nutrients with notable effects on sleep include:

  • Vitamin D: Research suggests that individuals who are deficient in vitamin D have a higher risk of sleep disorders. 
  • Magnesium: In addition to relaxing your muscles, magnesium has a mild calming effect. I often recommend 200–400 mg at bedtime for facilitating sleep. 
  • B vitamins: Vitamin B6 is important because it is involved in the production of melatonin, the sleep hormone. Vitamin B12 deficiency can cause insomnia as well, most likely because of its association with depression and circadian rhythm disruptions. 
  • Iron: The role of iron deficiency in insomnia is primarily related to restless leg syndrome. However, you should talk to your doctor about testing your iron level before taking iron supplements, as too much iron can be harmful. 

Alcohol Is a Double-Edged Sword 

Do you ever drink in the evenings to help you relax? It might help you fall asleep faster, but rather than improving insomnia, drinking alcohol can actually make it worse. Excessive alcohol disrupts sleep cycles and interferes with REM and other deep stages of sleep. 

If you drink, do so in moderation. The most recent National Survey on Drug Use and Health revealed that in the previous month, nearly 26% of Americans age 18 and older engaged in binge drinking (4+ drinks within two hours for women and 5+ for men)—and 6.3% are heavy drinkers (binge drinking five or more days in a month). This level of consumption is harmful not only for your sleep but for your overall health.

Medications That Can Cause Insomnia

The CDC reports that nearly half of our population has taken at least one prescription drug in the past 30 days, a quarter take three or more, and nearly 13% of adults are on five or more medications. Sleep problems are a documented side effect of a number of popular prescription and over-the-counter drugs, including:

  • Decongestants: Oral and nasal sprays that contain pseudoephedrine for nasal congestion 
  • Antidepressants: Prozac, Zoloft, Paxil, and other SSRI antidepressants 
  • ADHD drugs: Ritalin, Adderall, and other stimulant drugs prescribed for attention deficit hyperactivity disorder
  • Blood pressure drugs: Beta blockers and ACE inhibitors
  • Corticosteroids: Prednisone and related drugs used for inflammatory conditions 
  • Alzheimer’s drugs: Cholinesterase inhibitors such as Aricept 
  • Theophylline: A caffeine-like ingredient in some asthma meds
  • Thyroid replacement: Synthroid and other drugs for hypothyroidism, especially if the dose is too high 

Insomnia Due to Medical Conditions

Chronic disease affects every aspect of your life—including your sleep. Unfortunately, 6-in-10 adults of all ages have at least one chronic medical condition, and 4-in-10 have two or more. Not surprisingly, the burden of disease increases with age, which is one reason why older people have more sleep problems. Here is a partial listing of health challenges linked with insomnia:

  • Chronic pain: Sleep is difficult when you just can’t get comfortable. Whatever the source—arthritis, injury, cancer, or other illness—chronic pain can keep you tossing and turning at night.
  • Diabetes: Insomnia is a common complaint in individuals with diabetes. High blood sugar increases the need to urinate, and low blood sugar—often a consequence of insulin therapy—can cause nighttime episodes of hypoglycemia. Both of these can interfere with sleep. 
  • Heart disease: Whether it is trouble breathing due to heart failure, angina, or worrisome arrhythmias, several symptoms of cardiovascular disease are linked to insomnia. 
  • Thyroid: Sleep problems are a common sign of an overactive thyroid, but low thyroid function can also interfere with sleep. 
  • Parkinson’s: Insomnia in Parkinson’s disease is exceptionally common and is marked by frequent awakenings during the night.
  • Alzheimer’s: Even mild dementia is associated with insomnia, and it usually worsens over time. Problems include trouble falling asleep, waking up during the night or very early in the morning, and sleep apnea. Alzheimer's patients may also experience sundowning: increased anxiety, agitation, and confusion in the evenings and through the night. 
  • Urinary problems: Enlargement of the prostate and sleep disorders go hand in hand, as any man who has to get up and go two or three times a night can tell you. 

If you have a medical condition that is affecting your sleep, talk to your doctor. Treating these and other chronic diseases will improve sleep—and better sleep will improve many of these chronic conditions. 

The Healing Power of Sleep

Sleep is so essential that we spend about a third of our lives sleeping. If you are suffering with insomnia, make it a priority to find a solution. Your health depends on it.

Dr. Julian Whitaker

Meet Dr. Julian Whitaker

For more than 30 years, Dr. Julian Whitaker has helped people regain their health with a combination of therapeutic lifestyle changes, targeted nutritional support, and other cutting-edge natural therapies. He is widely known for treating diabetes, but also routinely treats heart disease and other degenerative diseases.

More About Dr. Julian Whitaker