What Is Sleep Deprivation?

Sleep deprivation is getting less sleep than your body needs. This differs, in part, based on your age, but also your needs as an individual. Sleep deprivation can obviously make you feel tired. But a lack of sleep, especially chronic sleep deprivation, can also cause you to develop impaired memory, oversensitivity to physical pain, hallucinations, altered blood pressure, and more.

Sleep Deprivation Symptoms

The effects of sleep deprivation vary throughout the day. For example, your symptoms will be worse during times when you would naturally be asleep (like overnight).

The most common symptoms of not getting enough sleep are what you probably expect—feeling sleepy and drowsy. Some people describe it as a strong desire to fall asleep or a sense of feeling run down. You can even have episodes of microsleep during which you suddenly and very briefly fall asleep when you're supposed to be awake, such as while driving or sitting in a meeting.

But there are other effects that are less obviously attributable to a lack of sleep. You might even go weeks without realizing that your problems are, in fact, due to sleep deprivation.

Common symptoms of sleep deprivation include:

• Mood and behavioral changes, which may include being short-tempered, anxiety, and depression
• Difficulty concentrating, which can result in decreased reaction times (e.g., that raise the risk of car accidents) and impaired work/school performance
• Problems with higher-level functions, such as planning, organization, and judgment
• Psychiatric symptoms of sleep deprivation, such as disorientation, hallucinations, and paranoia
• Physical effects, such as generalized discomfort (e.g., aches and pains) and gastrointestinal symptoms (e.g., upset stomach or diarrhea)
• A small overall decrease in your body temperature (feeling cold)

Why Sleep Deprivation Affects You

Your body functions based on a 24-hour cycle called a circadian rhythm. This rhythm coordinates waking and sleeping time, as well as hunger, digestion, body temperature, and hormonal functions throughout the day and night.

Sleep deprivation makes it hard for your circadian rhythm to function optimally, which impairs your body's overall functions.

Sleep also has a key role in learning, and it helps you consolidate the day’s events, solidifying and recording critical memories. When sleep becomes disrupted, alterations in the brain can cause these processes to become impaired.

Complications

Sleep deprivation can disrupt the natural flow of the sleep cycle, which can affect hormones (e.g., insulin, thyroid, growth) and can contribute to infertility.

Issues like mood or libido changes, weight fluctuation, and immune dysfunction can also occur, but might not affect everyone in the same way. For example, you could feel excited, depressed, or agitated. Or you may gain or lose weight, and you might become susceptible to infections or experience effects of inflammation (like an asthma attack).

While these contradictions may seem confusing, it's because hormones operate in a complex way—with positive and negative feedback loops that compensate for high and low hormone levels.

Furthermore, sleep deprivation can cause other substantial problems, including changes in blood sugar (and a predisposition to diabetes), blood pressure, pulse, and/or heart rate that can affect your long-term health.

Causes

There are many possible reasons for sleep deprivation. Perhaps you tend to stay up late and wake up early to catch up on everything you have to do. Your sleep might also be affected by your environment (e.g., you cannot avoid the sounds of street traffic at night).

While it can affect anyone, parents of babies and young children, caretakers, college students, and employees working long hours or multiple jobs are often sleep-deprived.

You may also experience sleep deprivation due to a medical condition. For example, pregnancy, a stomachache, or an upper respiratory infection can make it very difficult to sleep.

Caffeine, certain foods (like spicy foods), and some over-the-counter and prescription medications can interfere with sleep as well.

Sleep Disorders

Most sleep disorders make it hard for you to get a good night's sleep.

Insomnia, which is characterized by trouble falling asleep or staying asleep, is a common cause of sleep deprivation.

With obstructive sleep apnea, you might not notice that you are waking up at night. Though it may just be for a few seconds each time, those disruptions mean you aren't getting optimal sleep.

Restless leg syndrome may also cause nighttime waking, resulting in unnoticeable sleep deprivation with noticeable daytime fatigue.

Even nightmares can interfere with restorative sleep to the point that they deprive you of restorative rest.

Diagnosis

If you aren't sure whether or not you are sleep deprived, it is a good idea to get a professional evaluation if you notice any of the symptoms.

Sleep Assessment

Your healthcare provider will ask about your sleep habits and time spent sleeping when considering a sleep deprivation diagnosis.

Most humans have similar sleep needs, though there are variations. Average sleep requirements based on age can be used to figure out whether you might be deprived.

Beyond the number of hours, sleep quality is also important. Sleep apnea, anxiety, and chronic pain can compromise your sleep quality, even if you are lying in bed for the "right" number of hours every night. 

Your healthcare provider will also ask you how fast you fall asleep once you lie in bed. If you are sleep deprived, you will fall asleep almost immediately after putting your head down on your pillow. This is described as short sleep latency.

Your sleep latency can also be measured with a sleep study called the multiple sleep latency test.

Medical Evaluation

Your healthcare provider can identify some effects of sleep deprivation based on a physical examination and diagnostic testing.

Common signs of sleep deprivation include:

• Ptosis (droopy eyelids)
• Sluggish corneal reflexes (blink reflex)
• A hyperactive gag reflex (easily gagging during a throat examination)
• Hyperactive deep tendon reflexes (brisk reflexes when your healthcare provider checks your knee, ankle, or elbow reflexes)

Treatment

Ideally, preventing sleep deprivation will help keep you focused and full of energy. If you know that you have to stay up late, you could consider planning to sleep in that morning or the next day. And if you know that you have to get up early, going to bed early might do the trick.

Similarly, if you have a job that requires shift work or if you know that you'll be up in the middle of the night taking care of your baby, you could plan for scheduled naps every day to ensure that you get enough sleep.

Sometimes, though, sleep deprivation is unexpected and just happens due to a short-lived issue, like a pressing deadline. Most of the physical side effects of sleep deprivation are relatively minor and, thankfully, easily reversible.

Once you get a good night's sleep or take a nap, you may feel better within just a day or so if you have only been sleep deprived for a few days. However, most people need a while longer to recover from sleep deprivation that lasts weeks or longer.

If you have a medical problem, such as pain or cough, your healthcare provider may give you a prescription to help resolve or better manage it so that you can sleep.

If you really are having a hard time getting enough sleep due to insomnia, one of the surprising solutions is sleep restriction. If you can avoid taking naps, you are more likely to fall asleep when you want to so you can get back on track with your sleep schedule.

For persistent insomnia, medication may be needed.

Staying Alert

If you want or need to stay alert for a few hours until you can catch up on your sleep later in the day, there are a few strategies that can help. Moderate physical activity, pleasant lighting, enjoyable sounds (like music), caffeine, and doing something you are especially interested in can all help keep you alert for several hours until you can get some sleep.

But keep in mind that forcing yourself to stay awake when you're sleep-deprived can be dangerous if you need to drive or take care of something that involves concentration. Likewise, while this may get you through a tough day here and there, this isn't a strategy for the long term. Work to make changes that will allow you to get the rest you need when you need it.

A Word From Verywell

Sleep deprivation can have important consequences on your health, and, in extreme situations, may even lead to death. While you can negate the effects of short-term sleep deprivation, it is hard to know whether you can make up for sleep you lost months or years ago.

If you struggle to get sufficient sleep, talk to your healthcare provider so you can get professional help with your sleep deprivation. Whether your lack of sleep is due to a lifestyle issue or a health issue, your medical team can help you come up with a plan.