6 Reasons You Should Get More Sleep (And What to Do If You Can't)

According to experts, a good night’s rest is key for your health, productivity, and safety. Not convinced? Mental Floss spoke with Alon Avidan, director of the Sleep Disorders Center at the University of California-Los Angeles. He told us why should get more sleep—and what you should do if you’re having trouble logging the hours you need.

1. Sleep boosts your immune system.

Avidan says that sleep is needed for proper immune function. According to the Mayo Clinic, your body releases proteins called cytokines while you sleep, certain types of which help your body fight infections and reduce inflammation. You produce fewer of these productive proteins when you don't rest, along with lower levels of infection-fighting antibodies and cells. This might be why you’re more likely to get sick when you’re tired—and why you'll also stay sick longer. Meanwhile, a 2015 study in the journal Sleep confirmed how important getting some Zs is for the immune system: Researchers found that people who sleep six hours a night or less are four times more likely to catch a cold than people who get seven or more hours of shut-eye.

2. Sleep is necessary for memory function.

Sleep is also important for your memory. “We find that during sleep, the brain is very active in sorting out memory, and clearing memories that aren’t very relevant,” Avidan says. Research also indicates that sleep helps with the retention of memory. While the underlying mechanisms are still being studied, one study published in the journal Science hypothesized that new connections, called synapses, form between nerve cells during sleep and help memories stick.

3. Sleep affects your appetite—and therefore your weight.

Your memory isn't the only thing impacted by lack of sleep—your waistline is as well. “Appetite is tied to sleep,” Avidan says. “We find that with sleep deprivation, you run the risk of having more hunger. This is because your body releases more of a hormone called ghrelin. Ghrelin stimulates appetite, specifically for simple carbs, sugars, and fats. These are the food types that are more likely to lead to increase body mass index and put people at risk for obesity.”

Meanwhile, your body also produces less of an appetite-regulating hormone called leptin when you go without sleep. This phenomenon is clearly exemplified by studies that show that adults who sleep less than five or six hours a night face a higher risk of being overweight. Also, losing only a few hours of sleep for several days in a row can cause people to gain weight nearly immediately—mostly because they tend to overeat carbohydrates and other fattening foods.

4. Lack of sleep can make you feel—and act—drunk.

You also might have noticed that you sometimes feel loopy, or like your judgment is impaired, after you skip out on sleep. That’s because sleep deprivation produces impairments in cognitive or motor performance similar to those present after you’ve had a few drinks. In fact, staying awake for just 17 to 19 hours impacts your performance more than a blood-alcohol level of .05 and slows your reaction time by 50 percent. And staying up for 24 hours produces impairments in performance similar to a BAC of 0.10 percent.

Since a lack of sleep also lowers your decision-making capabilities, it’s harder to assess how tired you really are. Therefore, you continue to go about your day-to-day routine. Going to class or work while “tipsy” from lack of sleep is bad enough, but getting behind the wheel is even worse. “When people don’t get sufficient sleep, it’s almost similar to driving drunk,” Avidan says. If you’ve slept for only a few hours, use a cab or a ride share service instead of driving.

5. In certain cases, lack of sleep correlates with higher cancer rates.

Your cells also need sleep. According to Avidan, studies of sleep-deprived shift workers show that male workers have higher rates of prostate cancer and female workers have an increased incidence of breast cancer. “Not only is sleep necessary for cellular repair and immune function, it’s also necessary to help the body fight and prevent the conversion of healthy cells into more cancerous cells,” he says.

6. Sleep cleans out the brain (in a good way).

"Sleep is critical for the clearance of metabolites and toxins, which accumulate during the day,” Avidan says. “This is done primarily through the glymphatic system,” a system that drains waste products from the brain with cerebrospinal fluid. When you sleep, the cells in your brain may shrink, allowing the cerebrospinal fluid to wash away the built-up waste.

According to Avidan, the glymphatic system only kicks in while you’re sleeping. If you don't sleep, your brain isn't receiving the "cleaning" it needs—and the consequences might be dire. Researchers have found an accumulation of the protein beta-amyloid in the cerebral spinal fluid of sleep-deprived mice. Since beta-amyloid is associated with Alzheimer’s disease, scientists hypothesize that individuals who don’t get enough sleep are at risk for neurodegenerative disease. However, “this has never been really proven in humans, and the studies need to be done,” Avidan says.

How do I get more sleep?

Sleep restriction is also linked to pre-diabetes, heart disease, high blood pressure, shorter lifespans, and so on. Bottom line? A good night's sleep isn't a luxury—it's a necessity. However, lots of people have trouble getting the nightly seven-to-eight–hour rests that the NSF recommends for individuals for ages 18 to 65. "Any hour less than seven can put individuals at risk for the conditions we just spoke about," Avidan says. While a small population of sleepers called "short sleepers" have genetic predispositions that make them need less sleep than the typical person, what should other people—like students, shift workers, and people with sleep disorders—do to mitigate the harm from a sleepless night?

The first thing you should do is identify the source of your sleeplessness. If you've always been able to sleep soundly for seven to eight hours a night but you're suddenly sleeping way less, way worse, or you feel constantly fatigued during the day, you might have an untreated medical or psychiatric condition. (On the flip side, if you’re sleeping way more than usual, you could also have a problem.)

Some of the most common sleep disorders are sleep apnea, chronic insomnia, and restless leg syndrome; these can be treated by a medical professional. Other people might have anxiety that's keeping them awake or giving them nightmares. Those patients should see a sleep therapist, undergo cognitive behavioral therapy (a treatment in which patients identify negative thought patterns, challenge them, and replace them with realistic ones), and potentially go on medication.

Other people might have a shift-work schedule. Some individuals are able to get a sufficient amount of sleep, even with their fluctuating work hours. Those who can’t are at risk for shift-work schedule disorder, which includes excessive sleepiness when you’re awake, insomnia when you need to sleep, irritability or depression, and a slew of other symptoms.

“The way we generally recommend improve their sleep is to make sure that they get as much sleep opportunity as possible,” Avidan says. “Make sure the environment in which you’re sleeping is protected—it’s not noisy, it’s comfortable, it’s not too light.”

Also, avoid excessive light exposure while going home from work during the day. Wear sunglasses during the drive home, and don’t spend a ton of time outside. (In contrast, try to maximize your light exposure before you work an evening shift; this will help you stay awake longer.)

Still sleepy? Fifteen to 20-minute power naps are your friend. Avoid longer naps, as you’ll likely wake up during a deep sleep or REM sleep and feel groggier and more confused. The best time to take these naps is between 1 p.m. and 3 p.m., when most of us have a dip in our energy levels—not at the end of the day, which might throw off your sleep schedule.

Caffeine can also help. Just make sure you don’t drink it four to five hours before going to bed. And if things are really bad, there are various medications your doctor can recommend to manage daytime sleepiness.

The most common reason people are sleepy, however, is because of “behaviorally induced sleep deprivation.” That’s because they engage in activities and routines that don’t let them sleep enough. Avidan recommends removing electronics from your bedroom; making sure your sleeping quarters are comfortable, quiet, and dark; and limiting caffeine or alcohol before bed. Little things like cutting down on prolonged naps and leaving your iPad in the living room can also make a big difference.

Still having trouble getting rest? Instead of requesting medication right off the bat, try other things, like cognitive behavioral therapy with a sleep therapist. Hypnosis can also help.

It might take some strategic scheduling, planning, and lifestyle changes to get the good night's rest you need, but the health benefits you'll gain are worth the effort. This week, try some of the above sleep tips and see if they make a difference. In the meantime, good night and good luck!

A version of this story ran in 2016; it has been updated for 2021.