Are you experiencing insomnia and want to know why? Keep reading to learn 20 possible root causes for your lack of sleep!
Note from Dena: This post was written by Brianna Rivera, Dietetic Intern, as part of a research partnership between Back To The Book Nutrition and post-graduate nutrition students from the University of Houston.
One third of adults don’t get the recommended 7 to 9 hours of sleep each night (1). If you’re one of them, read on!
When it comes to sleep, quantity and quality both matter. Delays or interruptions to deep (REM) sleep compromise vital “rest and repair” functions your body is designed to perform all throughout the night.
Effects of Sleep Deprivation on your Health
Lack of quality sleep is associated with the following: (2, 3, 4, 5)
- Weight gain – Multiple studies have showed higher calorie intake, slower metabolism, and more weight gain in those who don’t sleep enough. One study showed the equivalent of a 10-15 pound weight gain per year when individuals slept 4.5 hrs vs 8.5 hrs per night. (30)
- Memory Loss – Poor sleep can lead to deterioration of the parts of the brain that are in charge of memory.
- ADD/ADHD – Sleep deprivation can worsen ADD/ADHD symptoms, and vice versa. Poor sleep quality interferes with neurological pathways that deal with alertness, attention, and arousal.
- Anxiety and Depression – Poor sleep quality has a circular relationship – it can be a cause and a result of the disorders.
- Lower Melatonin – Poor sleep decreases melatonin output, which can lead to increased cortisol. This reversal of our melatonin-cortisol rhythm is a key factor in HPA Axis dysregulation.
- Cortisol Imbalances – Cortisol, aka the “stress hormone,” rises with acute sleep deprivation, but in chronic sleep deprivation, levels are lowered.
- Other Hormone Imbalances – Growth hormone, leptin, and ghrelin are also negatively affected by lack of sleep.
- Infertility – Shift working women have a 33% higher rate of irregular periods and are 80% more likely to struggle with fertility than women with more typical sleep schedules. Sleep deprived men have nearly 30% lower sperm counts than those who report getting good sleep. (30)
- Higher Blood Sugar & Diabetes – 4 nights of poor-quality sleep in a row can lead to insulin resistance which, over time, can lead to the development of diabetes.
- Cardiovascular Disease – Less than 6 hours of sleep a night is associated with a 200% increased risk for heart attack and stroke, and a 400-500% increased risk for cardiac arrest. In addition, one night without enough sleep can raise systolic blood pressure by 17 points. (30)
- Suppressed Immune Function – Lack of sleep weakens the immune system, making us more vulnerable to both acute and chronic illnesses. One study showed nearly 3-fold increase in contracting the flu when induvial slept only 5 hours per night versus 7. (30)
- Higher Cancer Risk – A large European study showed 40% higher cancer rates among those who slept for 6 hours or less per night vs those getting 7 or more hours of sleep. Other studies have confirmed the sleep-cancer link. (30)
- Increased Inflammation -Poor sleep has been linked to long-term inflammation, which is a driver of most major chronic diseases.
- Autism Spectrum Disorder (ASD) – Autistic children have significantly altered circadian rhythms and get 30-50% less restorative REM sleep than non-autistic children. It’s unclear as yet whether this is a cause or effect of ASD. (28)
- Shorter lifespan – Many large studies have shown sleep deprivation to worsen the leading causes of death (heart disease, cancer, etc.) in the developed world. (30)
20 Root Causes of Insomnia
Lifestyle factors such as what you eat, physical activity, and your environment all play a part in your sleep cycle and lead to insomnia. Additionally, diseases, disorders, and medications can also disrupt your sleep. Here are 20 common root causes of insomnia:
1. Blood Sugar Imbalances
Multiple studies reported that diets high in refined carbohydrates were linked to increased odds of insomnia. Refined carbohydrates spike blood sugar. Insulin is then released, resulting in a rapid drop in blood sugar, causing disruptions to sleep. When blood sugar dips too low, adrenaline and cortisol are released, which are both known to interfere with sleep.
One study reported diets higher in refined carbohydrates, such as added sugars, white bread, and white pasta, increased the chances of developing insomnia in postmenopausal women, whereas, diets high in fiber, such as fruits and vegetables, had lower chances of developing insomnia (6).
Another study found that individuals that adhered to the DASH (Dietary Approach to Stop Hypertension) diet had lower odds of insomnia. This diet includes significant amounts of fruits, vegetables, and lower consumption of refined grains, sugar-sweetened beverages, and red and processed meat (7).
Consuming too much caffeine, or getting it too late in the day, hinders deep, restorative sleep…or may keep you from falling to sleep altogether! That’s because it takes 5-6 hours for only 50% of caffeine to exit the body. This does not just apply to coffee either!
Avoid these at least 6 hours before bed time. If you still struggle with sleep, try avoiding them entirely:
- Tea (opt for non-caffeinated herbal teas like Chamomile!)
- Hot chocolate
- Energy drinks
- Medications for headaches, PMS, etc that have added caffeine
- Weight loss pills that include caffeine
3. Alcohol Before Bed
Alcohol consumption first acts as a sedative (inducing sleep), but then can wake you 2 to 3 hours after blood alcohol concentration falls close to zero. Even if you don’t wake, this can cause a disruption to REM (deep) sleep (8, 9).
Alcohol also disrupts sleep by causing frequent overnight urination. Alcohol is a diuretic, and it blocks hormones in your brain that tell your kidneys to hold onto water. Instead, alcohol signals your kidneys to release more water, causing excessive urination (10).
4. Low Magnesium
Magnesium is essential for many processes in the body, including the maintenance of normal circadian rhythms. Aging is a major risk factor for magnesium deficiency. Low dietary intake of magnesium is also associated with depression, which can contribute to insomnia.
3. Vitamin D (Too much or too little)
However, one study revealed that higher dose vitamin D supplements (4,370 IU vitamin D3) actually lowered melatonin and worsened sleep (15). Interestingly, higher dose vitamin D supplements can deplete magnesium, so this may explain the link to poor sleep. Be mindful of magnesium intake when taking vitamin D!
6. Sedentary Lifestyle
Studies show that a sedentary lifestyle increases the risk of insomnia and sleep disturbances (16). Conversely, studies show people who exercise regularly sleep better. Just be mindful of the type of exercise you’re doing and the time of day you’re doing it, as explained below.
7. Exercising Too Late in the Day
Although regular exercise does help with sleep, exercising vigorously in the late afternoon or evening can actually disrupt sleep.
Before you sleep, your internal body temperature naturally cools down to induce sleep, but exercising too late in the day raises your temperature, releases endorphins, and increases cortisol production, all signaling your brain that it’s not time to sleep yet.
Less intense exercises like walking or gentle yoga are better options if you must work out closer to bedtime.
8. Blue Light
Studies suggest your phone, laptop, and TV could be the reason for your lack of sleep, especially if you’re exposed within an hour or two of bedtime! (17) All of these devices emit blue light. Blue light blocks melatonin, the “sleepy” hormone, and instead boosts your alertness (18).
9. Bedroom Temperature
Your body shifts its internal temperature throughout the day, and it has a direct effect on your sleep cycle. At night, your body decreases its body temperature, which in return, induces sleep.
When your bedroom is too hot or too cold, it can cause a disruption in your sleep cycle. 60 to 70 degrees Fahrenheit is suggested for optimal sleep.
10. Overnight Urination
Certain conditions and medications, as well as drinking too many fluids before bedtime, can disrupt sleep by causing frequent urination throughout the night.
The following can cause multiple trips to bathroom:
- Urinary tract infection (UTI)
- Overactive bladder
- Diuretics (aka water pills for hypertension and other conditions)
- Excess fluid intake (especially alcohol or caffeine)
11. Sleep Apnea
Sleep Apnea is a sleep disorder in which periods of breathing during sleep is disrupted – either completely stopping breathing or having episodes of shallow breathing. This is a very serious condition that can lead to numerous health conditions like insomnia, high blood pressure, and diabetes (19, 20). If you suspect you have sleep apnea, get evaluated by a doctor who specializes in sleep medicine.
12. Snoring/Mouth Breathing
Even if you don’t have sleep apnea, snoring and open mouth breathing overnight can contribute to lighter sleep and more overnight waking (for you and your sleep partner!). Consider exercises to increase nose breathing and/or consider mouth taping at night (the Buteyko web site is a fantastic resource for more info on both of these).
13. Stress / Cortisol
Stress impairs sleep by raising cortisol – aka the fight-or-flight hormone, and activates the HPA Axis, leading to arousal (21, 22). One study found that increased cortisol levels were directly linked to recurrent sleep problems (23). As mentioned above, poor sleep also raises cortisol, creating a vicious cycle.
Read more on ways to manage stress here!
14. Anxiety, Depression, & other Mood Disorders
What came first, the chicken or the egg? Studies show that anxiety and depression can be both a cause and a result of insomnia.
A study reported that individuals with insomnia suffered more severe symptoms of anxiety and depression opposed to those without insomnia (24). Another study of peri- and post-menopausal women found that difficulty falling asleep was strongly correlated with anxiety, while non-restorative sleep was strongly correlated with depression (25).
15. Low Serotonin
Serotonin, aka the “happy” hormone, is needed to make melatonin. When serotonin is decreased in individuals with depression, anxiety, and other mood disorders, or with gut dysfunction (most serotonin is made in the gut!), it decreases melatonin, lead to sleeping problems.
16. Hormone Shifts
Changes in estrogen, progesterone, and testosterone at times of hormonal shift (i.e., puberty, pregnancy, postpartum, starting or stopping hormonal birth control, perimenopause, and menopause) can disrupt temperature regulation and circadian rhythm.
Additionally, these hormones affect neurotransmitters like norepinephrine, serotonin, and GABA that also affect sleep (26).
17. Perimenopause & Menopause
61% of women experience insomnia during menopause due to ovarian hormone changes, hot flashes, restless leg syndrome, and obstructive sleep apnea. For many, these changes begin during perimenopause.
18. Thyroid Imbalances (High or low thyroid)
Hyperthyroidism (overproduction of thyroid hormone) can lead to insomnia due to increased body temperature, anxiety, and/or rapid heartbeat (27). Conversely, hypothyroidism (low thyroid) has been linked to trouble falling to sleep and shorter sleep duration (29).
19. Shift Work
Shift work (night shifts, swing shifts, etc.) has been linked to a variety of health risks, including sleep troubles – so much so that Shift Work Sleep Disorder (SWSD) is now a recognized condition. Unfortunately accidents and errors are much more likely among those with poor sleep so shift workers should make every effort to improve their sleep and circadian rhythm. (31)
20. Taking naps
Naps can help offset the decreased cognitive function that sleep deprivation causes, but they don’t replace deep overnight sleep and – for many – actually interfere with sleep (28).
21. Prescription or Over the Counter Medications
In addition to health problems, various prescription medications can disrupt sleep and increase the risk of insomnia. Ask your provider more about these medications, and whether they could be a cause of your insomnia.
- Sleep aids* (for insomnia) – Lunesta, Ambien, etc.
- Benzodiazepines* (for anxiety or insomnia) – Temazepam, Lorazepam, etc.
- SSRI’s (Selective Serotonin Reuptake Inhibitors) (for depression) – Prozac, Citalopram, etc.
- SNRI’s – (Serotonin Norepinephrine Reuptake Inhibitors) (for depression) – Cymbalta, Effexor, etc.
- Alpha-blockers (for high blood pressure) – Flomax, Cardura, Hytrin, etc.
- Beta blockers (for high blood pressure) – Toprol, Tenormin, Atenolol, etc.
- ACE inhibitors (for high blood pressure) – Lisinopril, Zestril, Enalopril, Vasotec, Lotensin, etc.
- Statins (for high cholesterol) – Lipitor, Lescol, Crestor, Zocor, Simvastatin, etc.
- Corticosteroids (oral, inhaled, or creams) (for inflammation, autoimmunity, asthma, skin rashes, etc.) – Hydrocortisone, Prednisone, Dexamethasone, Flovent, Budesonide, etc.
- Bronchodilators (inhaled for asthma, COPD, other lung conditions) – Albuterol, Formoterol, Theophylline, etc.
- Nasal/oral decongestants (for allergies/congestion) – Afrin, Sudafed, Ephedrine, Pseudoephedrine, etc.
- Psychostimulants (for ADD/ADHD) – Adderall, Ritalin, etc.
- Cholinesterase inhibitors (for Alzheimer’s, other memory conditions) – Aricept, Razadyne, Exelon, etc.
- Thyroid hormone replacement (for hypothyroidism) – Synthroid, Levothyroxine, Armour Thyroid, NatureThroid, etc.
- Headache/Migraine medications that contain caffeine or other stimulants – Excedrin, Midol, Migranol, etc.
* Sleep aids and Benzodiazepines are considered sedatives or hypnotics – they “knock someone out” but decrease the amount of deep REM sleep one gets, resulting in lest restorative sleep, poorer memory, lower immune function, and even increase rates of cancer and death with longer term use. (28)
22. Vitamins and Supplements
These are just a few vitamins and supplements that may disrupt sleep for some people, especially when taken later in the day.
- B Vitamins – Studies show that the intake of vitamin B complex had negative effects on sleep maintenance, and caused higher rates of insomnia (28, 29).
- Vitamin D – As mentioned above, vitamin D supplementation may deplete magnesium and/or melatonin, both of which could explain why it seems to disrupt sleep for some.
- Licorice – An excess intake of licorice can elevate blood pressure and cause headaches, making it difficult to sleep.
- Ginseng – Nervousness and insomnia are side effects of taking ginseng.
- Rhodiola – This herb may worsen anxiety symptoms in some individuals, especially those who are already sensitive to caffeine. High doses can cause insomnia, and it is recommended to take it earlier in the day opposed to the afternoon.
- Peppermint – More research is needed, but some individuals experience a stimulating effect after taking peppermint that may cause sleep disruptions.
About the Author:
Brianna Rivera graduated with a Master’s of Science in Nutrition from the University of Houston, where she is currently completing her dietetic internship. Brianna has strong interests in clinical nutrition, particularly diabetes and gut health. She is passionate about helping people get to the root of their medical issues – Nutrition! In her free time, Brianna loves to travel, be outside in nature, and practice yoga.
Disclaimer: Information on this site is intended only for informational purposes and is not a substitute for medical advice. Always consult with a trusted healthcare provider before implementing significant dietary change. Read additional disclaimer info here.