Why Can’t I Sleep?

Medically Reviewed by Jennifer Robinson, MD on September 12, 2023
4 min read

If you have trouble falling asleep or staying asleep, you’re not alone. The Institute of Medicine reports that between 50 million and 70 million adults in the U.S. have a sleep disorder. Nearly half of all adults report snoring, and more than one-third report that they get less than 7 hours of sleep in a typical night. What’s causing all this tossing and turning? There are several different reasons why you might be having trouble falling asleep or staying asleep or waking up too early.

Insomnia refers to general difficulty getting to sleep or staying asleep. The occasional sleepless night doesn’t mean you have insomnia. That happens to everyone from time to time. But if this is happening to you more frequently, you may have either short-term or chronic insomnia.

Sometimes people develop short-term insomnia during stressful times in their lives -- for example, if you’re going through a divorce or under pressure for a big deadline at work. You might also experience short-term insomnia due to jet lag after a long trip, this type of insomnia can last for up to 3 months.

Chronic insomnia is defined as having difficulty falling asleep or staying asleep, or experiencing “nonrestorative” sleep (a light sleep that doesn’t leave you feeling refreshed when you wake up in the morning) for an extended period, at least 3 months. People with chronic insomnia often have symptoms like daytime sleepiness, fatigue, irritability, depression, difficulty concentrating, and impairments in doing the tasks they need to do during the day.

What might cause chronic insomnia?

  • Poor sleep hygiene and habits, including consuming caffeine or alcohol right before bedtime, exercising late in the evening, following an irregular sleeping schedule (like sleeping late on the weekends to “catch up” on missed sleep during the week), and using your bed for wakeful activities like work and electronic devices
  • Long-term stress, including stress disorders like post-traumatic stress
  • Mental health conditions such as anxiety, depression, and bipolar disorder
  • Physical illnesses and pain conditions
  • Neurologic disorders, for example, people with Alzheimer’s disease often experience disruptions in their sleep
  • Side effects of certain medications, like antidepressants, blood pressure drugs, and medications to treat asthma

You may also have several of these factors interacting to lead to chronic insomnia. Other disorders can also cause sleep disturbances and contribute to insomnia.

If you snore loudly and wake up feeling unrefreshed, you might have sleep apnea. People with sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night. This condition affects more than 22 million people in the U.S., and can lead to other serious health problems, like high blood pressure and other cardiovascular issues, as well as poor performance on the job and increased risk of accidents.

Do you sometimes feel uncomfortable sensations in your legs, like aching, throbbing, itching, or pulling, and an irresistible urge to move them? You may have restless legs syndrome (RLS). These symptoms can get worse at night and when lying down, which often makes it hard to fall asleep or get back to sleep after waking up.

Circadian rhythms are part of your body’s internal clock, regulating your sleep-wake cycle. Circadian rhythm sleep disorders occur when your sleep schedule doesn’t match what your body needs. For example, if you do shift work that regularly requires you to work during the night and sleep during the day, you might have a hard time falling asleep during the time you have available, and feel sleepy at work.

In some cases, your body’s clock may be set just a little differently than the standard 24-hour sleep-wake cycle. For example, teenagers are often night owls, falling asleep well after midnight and inclined to sleep late in the morning (something that doesn’t work well with school schedules). Older adults, by contrast, often experience “advanced sleep phase disorder,” meaning that they are inclined to wake up before dawn and fall asleep quite early.

Although sleep experts agree that most adults need 7-8 hours of restorative sleep per night for optimal wellness, not everyone is the same. Some people appear to have genetic variations that naturally produce a need for less sleep. So if you are regularly going to bed at 1 a.m. and waking up at 5 energetic and raring to go, maybe you’re one of those lucky few. And if you just have a temporary interruption in your schedule or a high-pressure period at work or school that’s getting in the way of your sleep for a couple of weeks, there’s probably no need to see a doctor.

But if your insomnia, snoring, or restless legs are disrupting your daily life, making you feel fatigued, moody, irritable, and unable to get your work done, and this pattern is persisting over time, then it’s time to talk to your doctor. There are many effective treatments for sleep disorders. You don’t have to be awake all night and dragging all day!