Reasons Why You Can’t Sleep

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Do you find yourself asking "why can't I sleep?" Are you tired of waking up more tired than when you went to bed? Does it seem like a good night’s sleep is more elusive than your half-remembered dreams?

If you’ve been having a tough time falling or staying asleep, chances are the cause is either something you’re doing or something you’re not doing. Fortunately, there are a number of steps you can take to address the problem.

Symptoms

There are some common signs that you might not be getting enough sleep. Some of these include:

  • Difficulty concentrating
  • Excessive daytime sleepiness
  • Irritability
  • Lack of energy
  • Mood changes
  • Slowed thinking
  • Poor attention span
  • Poor memory
  • Trouble making decisions

If you can't sleep at night, you may find yourself feeling groggy and drowsy most of the next day. You may also drift off during the day or consume excessive amounts of caffeine to try to stay awake.

Why You Can't Sleep

There are many different factors that can contribute to trouble with sleep. Lifestyle choices, poor sleep habits, stress, and medical conditions can all play a role.

Alcohol

A single glass of wine may not interfere with your ability to drift off. But indulge in much more alcohol before bedtime and you’ll probably find that your sleep is impaired.

The initial effect of alcohol is relaxation, so you’ll probably drop off to sleep quickly after imbibing. But alcohol interferes with your sleep cycle, especially the REM sleep that includes dreaming. The result is fragmented, unrefreshing rest. Plus, you’re likely to wake up needing to use the bathroom during the night, a definite hit to your sleep quality.

Poor Sleep Habits

Your sleep habits can also play a part in poor sleep. Habits that can make it harder to fall and stay asleep include:

  • Staying up too late
  • Watching television in bed
  • Playing on your phone in bed
  • Having an irregular sleep schedule

Fortunately, these problems can also be remedied by making relatively small changes to your nightly habits.

Sharing Your Bed

Sharing your bed with someone, whether human or four-legged, greatly reduces the quality of your sleep—especially if your partner snores, crowds you, hogs the covers, or otherwise makes you uncomfortable. You and your human partner might also have a mismatch on preferred sleeping conditions, such as temperature, light, and noise level.

Poor Sleep Environment

Most sleep experts recommend keeping your bedroom at a moderate 65 to 72 degrees Fahrenheit at night, but many people like to cut energy costs by turning the thermostat down to the freeze zone during the winter and switching the AC off during the summer.

Both of these extremes hijack your trip to the land of Nod, however. Your body needs to cool slightly at night for the most refreshing sleep, which is impossible in an overly heated bedroom. A too-cold room, on the other hand, will wake you up.

Light exposure at bedtime also impairs your quality of sleep, whether it’s coming from your bed partner’s reading lamp, the television, or outside your window. For some people, even the glow of a bedside alarm clock is enough to signal their brain that it’s time to wake up.

Caffeine

You know a bedtime cup of coffee is a bad idea, but did you know that the half-life of caffeine is three to five hours? That means only half the dose is eliminated during that time, leaving the remaining half to linger in your body. That’s why a late afternoon cup of joe can disrupt your sleep later that night.

Stress

Probably the most common non-medical reason for short-term insomnia is a mind filled with worries or stress. During the day, the activities of life tend to distract you, but once you settle yourself into bed, your mind is free to roam. For most people, it’s not the good aspects of their lives that their mind chooses to focus on, but rather, the negatives.

Exercise

A casual around-the-block stroll with your dog in the late evening is fine (especially if it shifts your pet's wake-up time closer to your own). But a heart-pumping, sweat-dripping cardio workout within three hours of your own bedtime is too much.

Your body temperature and heart rate naturally drop as you fall asleep. Exercise raises those two body functions and stimulates your entire nervous system, making it tough to snooze.

The Wrong Snack

Is your typical bedtime snack a slice (or two) of pizza or a bag of chips? If so, don’t be surprised when you’re lying awake staring at your ceiling.

A full load of fat or protein right before bedtime sends your digestive system into overdrive, making it difficult to sleep and potentially giving you heartburn. But hunger pains can wake you up as well, as can precipitous blood sugar drops during the night

It is also important to note that other factors including sleep disorders and depression can also make sleep difficult. If you suspect that a medical or mental health condition is contributing to your poor sleep, you should talk to your doctor.

Effects of Not Sleeping

Sleep deprivation can have a wide range of negative health effects. Some of the major physical and mental health consequences include:

  • Anxiety
  • Bipolar disorder
  • Cardiovascular disease
  • Depression
  • High blood pressure
  • Hormone imbalances
  • Obesity
  • Type 2 diabetes
  • Weakened immune system

In addition to these health problems, lack of sleep is also connected to an overall decrease in quality of life and a greater risk of death.

How to Sleep Well

Work to alleviate some of the sleep-stealers that are affecting your rest. These strategies may improve the amount and quality of sleep that you get each night.

  • Limit alcohol use, especially in the evening.
  • Give your pets beds of their own, encourage your snoring partner to sleep on their side, and use a white-noise machine to block out sound.
  • Adjust your thermostat to avoid being too hot or too cold. If that's not possible, wear thick socks to a well-blanketed bed during cold snaps and use a fan in the summer. 
  • Turn off electronics at least an hour before bedtime.
  • Hang blackout shades or curtains and close your bedroom door to shut out light.
  • Although caffeine’s effects on you depend on your tolerance, the dose, and your age, it is best to keep your consumption below 400 mg per day and stay away from caffeine sources after lunchtime. 
  • If you're struggling with stress, try a daily meditation practice. You don’t need to be an expert yogi or spend hours sitting on a mat. Even 10 minutes a day is beneficial. 
  • Schedule your workout for the morning, or hit the gym during your lunch hour.
  • Have a small snack before hitting the hay. It should be heavier on complex carbs and lighter on protein, but include both. Good choices include a small bowl of whole-grain cereal and milk, a slice of deli turkey wrapped around a celery stick, or a piece of fruit spread with peanut butter.

A Word From Verywell

If you are wondering why you can't sleep, the first thing you should do is assess and address any lifestyle factors that might be interfering with a good night's rest. But if you don't find any relief after making these changes, talk to your doctor. They can help get to the bottom of your sleep difficulties and find the appropriate treatment so you can get the rest you need.

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3 Sources
Verywell Mind 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.
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