How Sleep Affects Your Health

Medically Reviewed by Carol DerSarkissian, MD on February 21, 2022
5 min read

Sleep does more than make you feel rested. It’s a crucial part of life. During slumber, your body is hard at work. Your muscles repair themselves, your brain sweeps out waste, and memories are formed. Your body also releases hormones that play a role in everything from your hunger to stress levels.

It’s not surprising, then, that sleep is tied to your overall health. People who regularly miss out on it have a higher chance of having problems like obesity, depression, diabetes, and heart disease. On the flip side, many of those health issues can also set the stage for sleep trouble.

Too little shut-eye can lead to a bigger waistline. One reason could be that when you don’t get enough sleep, your body makes more ghrelin, a hormone that makes you hungry. You also have lower levels of leptin, a hormone that controls your appetite. As a result, you tend to eat more, which can lead to weight gain. If you’re short on sleep, you could also be less likely to have the energy to exercise. In fact, one study found that women who got 5 hours or less of slumber were 15% more likely to become obese than those who logged at least 7 hours.

Overweight can also take a toll on your rest. Extra fat around your neck may block your breathing during sleep, a condition called sleep apnea. Obesity may also raise your chances of having restless legs syndrome. You may twitch and kick at night, which interrupts your slumber. If you often feel exhausted during the day, talk to your doctor. They can talk to you about your symptoms, do a physical exam, or refer you to a sleep specialist to figure out what’s going on.

It’s not clear exactly why sleep and dementia are linked, but there are a few theories about the effects that show up in the brain.

During deep sleep, your brain sweeps away waste called amyloid proteins. Research suggests that if you don’t log enough slumber, these proteins build up. They form clumps called plaques. It’s thought that these plaques affect how brain cells work. Over time, this may lead to dementia, including Alzheimer’s disease.

High levels of amyloid plaque can also keep you from getting enough deep sleep. Many people with Alzheimer’s disease also get confused or anxious in the evening, a problem called sundowning. This can affect their rest. A regular bedtime routine and avoiding caffeine or alcohol in the evenings may help.

Sleep deprivation causes your body to release less insulin, a hormone that controls blood sugar. It also makes your cells less sensitive to insulin. Over time, too-high levels of blood sugar can lead to type 2 diabetes. Research shows that people who don’t snooze enough are nearly twice as likely to develop the disease. The kind of slumber you get matters, too. The deepest stage of sleep plays a large role in blood sugar control. That could be why conditions that interrupt your sleep, such as sleep apnea, are linked with diabetes.

On the other hand, diabetes can set the stage for sleep issues. Classic symptoms of uncontrolled blood sugar are thirst and needing to pee often, which could keep you up during the night. Or you may wake up feeling dizzy, sweaty, or shaky because of low blood sugar. Diabetes also raises your risk for sleep apnea and restless legs syndrome.

To preserve good sleep and control diabetes, work with your doctor to keep your blood sugar in check.

Good sleep and your mental health go hand in hand. A lack of quality slumber can interfere with your brain activity. This may dampen your mood and thinking. In fact, having insomnia raises your odds of having depression or anxiety more than tenfold.

Depression and anxiety can also trigger sleep problems, including trouble falling or staying asleep. The opposite may also happen: You may end up sleeping more than normal. Treating your anxiety or depression with therapy, medication, or both can help you get the sleep you need. Research shows that cognitive behavioral therapy works for insomnia.

When it comes to your heart, getting the right amount of sleep is important. When you sleep, your body regulates your stress hormones. If you don’t get enough rest, those hormones stay high, which could lead to high blood pressure. Plus, sleep deprivation can lead to weight gain and diabetes, which are all trouble for your heart.

But more sleep isn’t always better. Getting too much is also linked to heart disease. Although experts aren’t sure of the exact reason why, they think that oversleeping may be a sign of another underlying health issue. It could also signal that you aren’t snoozing soundly. Aim to get 7 to 8 hours of sleep each night for your heart’s sake.

It’s no secret that a cough and stuffy nose can keep you up at night. But not getting enough sleep raises your odds of catching a cold in the first place. It reduces your levels of the antibodies, cells, and proteins called cytokines that your body uses to fight viruses. You may also need longer to recover if you don’t get enough rest.

If you’re under the weather, make rest your No. 1 priority. To ease the nighttime coughs and congestion, sip a tea with honey, take over-the-counter medicines, and hop in a steamy shower before bedtime. In the bedroom, try propping yourself up with pillows and running a humidifier.

Your internal clock, or circadian rhythm, controls when you want to sleep. Research suggests that throwing off this schedule can raise your chances for certain cancers, such as breast, ovarian, colorectal, and prostate.

Are you getting treatment for cancer? Medicines, hot flashes, fatigue, and pain can disrupt your slumber. Speak to your doctor. Good sleep habits, relaxation techniques, and therapy may help you get a good night’s rest.

Science is less clear about the link between sleep and kidney disease, but some research shows that your circadian rhythm may also play a role in how the organs work. In one study, women who got too little sleep had a greater chance of having a rapid drop in their kidney function. This may set the stage for kidney disease.

If you have kidney disease, getting a good night’s sleep may be harder. You’re more likely to have a sleep disorder, such as sleep apnea, insomnia, or restless legs syndrome. That may be because dialysis affects your circadian rhythm. Or it could be brought on by a condition tied to kidney disease, such as depression, diabetes, or heart disease. Speak with your doctor, who can prescribe the right treatment.