Why Can't I Sleep at Night?

Feb 24, 2021 Sleep Tips 7 MIN

Why Can't I Sleep At Night

Everyone has those days when your body feels tired, but you are still unable to fall asleep. Lying in bed without being able to fall asleep despite feeling exhausted can be a frustrating experience, especially when it happens regularly. Without a good night’s rest, you’re left feeling drained the next day.

Figuring out why you can’t sleep can be challenging, and sometimes there is more than one reason for sleepless nights. Identifying the reason why you can’t sleep can help you fix the root of the problem and get you one step closer to feeling rested throughout the day. 

How much sleep is a ‘good’ amount of sleep? What is considered a normal amount of sleep is different for every person. On average, adults need about seven - nine hours of uninterrupted sleep per night, with some people needing more or less than this amount.6 Implementing healthy sleep habits is important for maintaining both physical and mental health. 

For most people, experiencing occasional sleeplessness, or the inability to fall asleep is quite normal and not a cause for medical concern. But, pay attention to how frequently this problem persists, as it could also be a sign of a sleep condition that require you to speak to your medical professional of choice.

Learn More: Everything You Need to Know About Melatonin

The Sleep Cycle

The way you sleep is tied to your ‘sleep-wake’ cycle.  

Your body’s biological clock, also called the circadian rhythm, is responsible for carrying out many normal processes within the body, and the sleep-wake cycle is one of these processes.  Circadian rhythms are tied to a master clock in the brain to help your body respond to habitual activities that happen around the same time every day, like eating and sleeping. This biological clock is wired by certain genes in the body that respond to external cues, such as light and sound, throughout a 24-hour period. The presence of light during the daytime signals the clock to help us remain alert and awake throughout the day, while darkness stimulates the release of the hormone, melatonin, which promotes sleep.4  

One of the reasons people experience sleeplessness could be due to disturbances in the circadian rhythm that regulates the sleep-wake cycle. Since these are strongly linked to your environment, this means that there are certain factors you can change to stabilize your sleep-wake cycle and help you sleep better Let’s take a look at some factors that can alter your sleep cycle and keep you from achieving a good night’s sleep. 

Learn More: How Much Melatonin Should You Take?

8 Reasons You Can’t Sleep at Night 

1. Too Much Caffeine 

Drinking too many caffeinated beverages, such as coffee, tea, or energy drinks, can impede your ability to sleep at night. The later you consume caffeine in the day can negatively impact sleep quality. Research has found that consuming caffeine up to six hours before bedtime can impair the length of time that people are able to sleep continuously. In fact, caffeine can last up to 16 hours in the body. 

Take stock of how much caffeine you are consuming throughout the day. For healthy adults the FDA has cited 400 milligrams a day (four or five cups of coffee) as not having negative effects, but if your caffeine intake is more than this it could be disrupting your sleep patterns.7 Opting to skip on that late afternoon coffee can help you fall asleep and stay asleep throughout the night.2 

2. Napping 

Taking naps during  the day can help some people perform daily activities better and feel energized later in the day. However, taking long naps or naps later in the day close to bedtime could be interfering with your ability to fall asleep. Napping also does not provide the same health benefits as REM sleep at night, so it’s important to limit the amount you nap in a way that it does not interfere with your bedtime routine. 

Taking a short 15 to 30-minute ‘power’ nap around the same time of day can help your biological clock register this in your sleep-wake cycle, thus supporting better sleep at night as well.2 

3. Using Your Bed for Reasons Other Than Sleep 

If you routinely spend time lying in your bed during the day, or use your bed to work or watch TV, you might have trouble sleeping in it at night. Try to separate your activities other than sleep to another area of your bedroom or house, to help improve sleep quality at night. 

4. Stress

Feeling stressed before bedtime is a big factor that prevents getting good sleep throughout the night. If your mind is busy right before going to sleep for the night, this can activate your stress hormone and negatively impact your sleep. There are certain measures you can take to prevent yourself from having active thoughts or stress before you sleep. When learning how to get better sleep, it is recommended to avoid conversations and activities that are likely to elevate stress levels closer to bedtime.3 Try to set aside a time earlier in the day to think, discuss or write about the issues that keep you awake at night, and try to do something that relaxes you before settling into your bedtime routine. How about reading or listening to soft music? You can also try breathing or progressive muscle relaxation exercises, meditation or a warm bath or shower to help you relax and drift off to sleep.  If turning everything off is hard for you, consider sleep gummies with l-theanine to help relax the mind at night.8† 

5. Stimulating Activity Before Bedtime 

Working on your laptop, watching TV in bed, and scrolling through social media on your phone are all sources of light from electronic screens that can interrupt your sleep-wake cycle by disturbing your biological clock. The blue light that comes from electronic screens has been shown to decrease melatonin production, making you feel less sleepy. These activities can also make your brain more active right before you try to sleep, which is counterproductive. Try to strictly turn off your electronics at least one hour before bedtime and see if that helps you experience a good night’s sleep. 

Strenuous exercise before bedtime can also interfere with your ability to sleep at night. A heavy workout can increase your heart rate, body temperature and energy levels instead of the relaxation you need before turning in for the night. 1 

6. Snacking Before Bedtime

Are you in the habit of snacking before bedtime? Depending on what you eat, you might have trouble sleeping at night. Eating foods that are heavy in fat or protein that require heavy digestion can interrupt good sleep at night. So, even if that leftover pizza looks tempting, if you have trouble sleeping, it’s wise to skip. If you find yourself hungry after dinner have a light snack instead. It’s also a good idea not to eat excessively spicy food, or drink liquids right before bedtime. Getting up to go to the bathroom at night is another reason you might not feel rested the next day. 1 

7. Alcohol consumption

Alcohol consumption before bedtime is another known trigger for impacting sleep quality. The negative effects of alcohol on sleep are dose dependent, the more you drink the more it can negatively affect sleep quality.  Drinking a lot before you go to sleep causes fragmented sleep, and doing this regularly can impair your normal sleep pattern. Alcohol in moderation might help you feel relaxed, but if you’ve recently started having trouble staying asleep, try to notice how much alcohol you consume and how close to bedtime. Limiting how much you drink at night may help you solve your pattern of sleep disturbance.  

8. Your Sleep Environment 

The sleep cycle is sensitive to where you sleep at night. If you sleep in an area that is somewhat noisy, or has light coming in through the windows, this can disturb your circadian rhythm. If your bedroom is too hot or too cold, it can cause you to wake up drenched in sweat or chilled. Sleep experts recommend keeping your room slightly cooler at night than you would have it during the day to help you sleep well. Experts say that the optimal temperature for sleep is between 66-70 degrees Fahrenheit, so be sure to adjust your thermostat accordingly. 9 In the winter, this means it might help to sleep with an extra blanket or socks to prevent waking up from feeling too cold, and in the summer, while it might be tempting to turn off your thermostat for the night, being too hot at night could be interrupting your ability to sleep well. 

How to Improve Your Sleep Pattern 

If the question of “why can’t I sleep at night?” is posing a persistent problem, you might have to consider several of these factors for reasons that are keeping you up at night. Regulating your sleep-wake cycle is your best bet for getting consistent deep sleep at night, but it can take time to figure out what works best for you. Changing your sleep habits can be challenging, but it is worth the effort. Getting proper rest can help you feel more active and alert during the day and it can prevent more serious health problems. 

If you are experiencing regular trouble sleeping be sure to consult your healthcare provider. Taking certain sleep supplements such as a melatonin supplement on occasion, may help support a good night’s sleep by helping you regulate your sleep-wake cycle.

Learn More: Can You Take Melatonin Every Night?

† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.


  1. “Get Moving to Get Better Sleep” National Sleep Foundation. Accessed on February 24, 2023. https://www.thensf.org/get-moving-to-get-better-sleep/
  2. O’Callaghan, F., Muurlink, O. & Reid, N. Effects of caffeine on sleep quality and daytime functioning. Risk Management and Healthcare Polic.2018; 11: 263–271. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292246/
  3. Suni, E. “What to Do When You Can’t Sleep.” 2023. SleepFoundation.org. Accessed on: January 11, 2023. https://www.sleepfoundation.org/insomnia/treatment/what-do-when-you-cant-sleep
  4. Suni, E. “Circadian Rhythm.” 2022. SleepFoundation.org. Accessed on: January 10, 2023. https://www.sleepfoundation.org/circadian-rhythm#
  5. Fry, A. “Napping.” 2020. SleepFoundation.org. Accessed on: January 11, 2022. https://www.sleepfoundation.org/sleep-hygiene/napping
  6. “How Much Sleep Do You Really Need?” National Sleep Foundation. Accessed February 24, 2023. https://www.thensf.org/how-many-hours-of-sleep-do-you-really-need/
  7. “Spilling the Beans: How Much Caffeine is Too Much?” FDA. Accessed February 24, 2023. https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much#:~:text=For%20healthy%20adults%2C%20the%20FDA,associated%20with%20dangerous%2C%20negative%20effects.
  8. Newsom, R. “Relaxation Exercises To Help Fall Asleep” Sleep Foundation. Accessed February 24, 2023. https://www.sleepfoundation.org/sleep-hygiene/relaxation-exercises-to-help-fall-asleep
  9. Brues, M "Sleep Hygeine" The Sleep Doctor. 2022. Accessed on February 24, 2023. https://thesleepdoctor.com/sleep-hygiene/


Melissa Dorval Pine, RD

Senior Manager, Medical and Scientific Communications

Melissa is a Registered Dietitian and provides leadership to Pharmavite’s Medical and Scientific Education team. She has over 20 years of experience educating consumers, healthcare professionals, retailers and employees about nutrition, dietary supplements, and overall wellness. Prior to joining the Medical and Scientific Communications team, Melissa launched and managed Pharmavite’s Consumer Affairs department and worked as a clinical dietitian throughout Southern California. Melissa received her Bachelor of Science degree in Nutritional Sciences from the University of Arizona in Tucson, Arizona, and completed her dietetic internship at Veteran’s Hospital in East Orange New Jersey.

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