How Sleep Deprivation Affects the Human Body

Sleep deprivation happens when you do not get enough sleep to meet your body's needs. If you're sleep-deprived, you may feel tired. You can also have other symptoms, because sleep affects your whole body.

You may worry about what will happen if you don't get enough sleep. You might wonder if sleep deprivation will have lasting physical effects on your body. This article will look at what research says about the short- and long-term consequences of sleep deprivation on your health.

How Sleep Deprivation Happens

Sleep deprivation occurs when you get less sleep than your body needs to function. You can be sleep-deprived in the short term, as in the day after you slept poorly (acute) or long term (chronic) if you consistently are unable to get enough sleep.

Sleep deprivation can happen in one night or over weeks, months, or even years. If you need 9 hours of sleep to feel rested, you may become sleep-deprived if you regularly get 8 hours of sleep.

The cure for sleep deprivation is to get more sleep. However, that's not always easy to do—the fix for sleep problems depends on what's causing them.

Not getting the sleep you need negatively affects your physical and mental health in a number of ways. You'll feel some of these effects right away, but others may not show up for years.

Brain and Nervous System

The effects of sleep deprivation on the brain can be similar to the effects of alcohol on the brain. In fact, research has shown that driving when you're sleep-deprived can be as dangerous as driving while you're intoxicated.

If you are sleep-deprived, you may have:

• Slurred speech
• Uncontrolled reflexive movements of your eyes (nystagmus)
• Shakiness or tremors in your hands
• Droopy eyelids (ptosis)

Abnormal Reflexes

There are other neurological reflexes that are also affected by sleep deprivation.

You may not have any symptoms related to these changes, but if your healthcare provider were to test your reflexes, they would be abnormal.

For example, you may have:

• Slow (sluggish) corneal reflexes
• Oversensitive (hyperactive) gag reflex
• Oversensitive (hyperactive) deep tendon reflexes

Seizures

One of the most serious consequences of not getting enough sleep is that it can make you more likely to have a seizure. People who have epilepsy are at a higher risk for seizures when they are sleep-deprived.

Pain

You might be more likely to feel feel pain when you're sleep-deprived. Research has shown that sensitivity to heat and pressure pain is higher when we have not had enough sleep.

Other studies have found that people who are sleep-deprived can be more sensitive to pain in their esophagus. That might be one reason why people get heartburn or gastroesophageal reflux disease (GERD) at night.

Sometimes, people with ongoing pain that stems from sleep deprivation are diagnosed with fibromyalgia or other chronic pain conditions.

Vital Signs

Studies have shown that sleep deprivation may cause small changes in your vital signs. Your vital signs are measurements that healthcare providers use to assess your overall health.

Vital signs that can be affected by sleep include:

• Body temperature
• Blood pressure
• Heart rate
• Breathing rate (respiratory rate)

The changes in your vital signs related to sleep deprivation are usually not very big. For example, your body temperature might only go down a little bit.

Your breathing might also change slightly. When sleep-deprived people do sleep, they tend to have longer and more frequent pauses in their breathing (apnea).

Hormones

Sleep deprivation can change how hormones are released by the endocrine glands. Hormones that follow a circadian pattern are the most likely to be affected by sleep.

Growth in Childhood

The effects of sleep loss or disruption in children can be a very big deal. For example, kids that don't get enough sleep may have problems with their growth.

Growth hormone is secreted during slow-wave sleep. In children, this kind of sleep is common in the early part of the night.

However, if this period of sleep is disrupted—either because a child isn't getting enough sleep or they have a condition like sleep apnea—it affects how much growth hormone gets released.

As a result, children may not reach their full growth potential. They might be shorter than they would have been if they had gotten enough growth hormone.

Thyroid Function

Sleep deprivation can also change how the thyroid gland works. Staying awake for a long time increases your energy needs. In turn, your thyroid has to work harder to keep up.

Sleep problems can also be a symptom of thyroid disorders.

Skin

If you've ever been told that you look tired, you know that it can be hard to hide when you haven't had a good night's rest.

Sleep deprivation makes you look tired or rundown in a few ways. One is that it can give your skin a sallow, dull look. You may also have bags and dark circles under your eyes.

Your skin needs support from your hormones to rebuild and stay elastic. When you have hormones that aren't working optimally and poor circulation to your tissues, it creates that dull, rundown look of exhaustion.

Other Hormones

Sometimes, the relationship between sleep and your hormones is a vicious cycle. Some hormones are not just affected by sleep deprivation but may contribute to it.

Aside from thyroid and growth hormones, other hormones that are involved in sleep include:

• Cortisol
• Adrenaline
• Catecholamine
• Luteinizing hormone
• Follicle-stimulating hormone
• Testosterone
• Progesterone

Imbalances in hormones are most often linked to reproductive health problems, like changes to the menstrual cycle and infertility. However, you can also have symptoms related to other body systems that rely on hormones to function.

If your sleep is affecting your hormone levels, you may have symptoms throughout your body. Many of these symptoms are common in people who are going through menopause.

Hormone-related symptoms you might experience include:

• Hair thinning and hair loss
• Hot flashes, sweating, night sweats
• Cold hands and feet
• Feeling more or less hungry/thirsty than usual
• Nausea, constipation, and/or diarrhea
• Headaches
• Brain fog, depression, and anxiety
  

Long-Term Health Risks

Sleep deprivation can negatively affect your health in both the short and long term. It can even increase your risk of dying.

Metabolism

Not getting enough sleep can affect your metabolism. If your metabolism is not working, it can lead to glucose intolerance and weight gain. Being overtired also makes it less likely that you'll want to take part in regular physical activity.

At the same time, changes in the hormones that make you feel hungry and full can happen when you haven't gotten enough sleep. Eating more and moving less can also lead to weight gain over time. These factors all increase your risk for chronic health conditions like diabetes.

Immunity

There is some evidence that sleep deprivation has a negative impact on immune function. If your immune system isn't working, you might get sick more often. When you do get sick, you might get more ill and take longer to get better.

Cancer

Researchers have started to look at whether chronic sleep deprivation may contribute to the risk of cancer. However, more research is needed to prove that there is an important link.

Dementia

Not getting enough sleep affects your brain. Over time, you might be more likely to develop memory problems and conditions like dementia. Research has suggested that the risk for dementia is especially linked to not getting enough sleep when you're middle-aged.

Can You Die From Sleep Deprivation?

There have been cases of people who died from being completely deprived of sleep, but most of them had a rare condition that causes severe insomnia.

Not getting enough sleep is not likely to cause death directly. Instead, it can increase your risk of dying from other causes.

For example, if you're very tired, you might be more likely to get into a car accident. You might even fall asleep while you're driving.

Being sleep-deprived can also make you more likely to get injured when you're working, exercising, doing a hobby, or even just going about your daily routine.

Summary

Sleep deprivation can have serious consequences for your physical and mental health. In the short term, you might have changes to your reflexes and vital signs.

Over time, not getting enough sleep can increase your risk of chronic health conditions and might even increase your risk of dying.

A Word from Verywell

It's important that you do your best to meet your sleep needs. That means figuring out how many hours of sleep you need each night to feel rested.

Beyond the number of hours, the quality of your sleep is also important. If you're not getting quality sleep, it's important to find out why. For example, having sleep apnea and other health disorders can make it harder to get enough good sleep.

If you're having trouble sleeping, talking to a healthcare provider who is board-certified in sleep medicine can be beneficial. They can test you for different sleep disorders and help you find a treatment.

For example, if you have trouble falling asleep or staying asleep, cognitive behavioral therapy for insomnia (CBTI) might help.