What Happens to Your Body When You Don’t Get Enough Sleep?

Feeling sluggish, hazy, or just plain tired? While there are dozens of explanations for symptoms like these, it’s quite possible that the most logical one is true—that you’re not simply not getting enough sleep. Unfortunately, millions of us are chronically sleep-deprived.

According to the Centers for Disease Control and Prevention (CDC), one-third of U.S. adults report usually getting less than the recommended amount of sleep. The problem of sleep loss has become so prevalent that the U.S. Department of Health and Human Services has listed “increase the proportion of adults who get enough sleep” as one of the goals for its Healthy People 2030 project. 

While one night of tossing and turning should not cause major concern, a pattern of poor sleep can wreak havoc on your health. Here’s a look at what happens to your body when you don’t get enough shuteye. 

How Much Sleep Is Enough?

There’s no one-size-fits-all definition for getting “enough” sleep. In general, though, most adults need at least seven hours of sleep per night. You’ll know you’re getting enough sleep if you wake up feeling refreshed. Plus, the ability to wake up naturally without an alarm clock is another indicator that your sleep schedule is sufficient. 

On the other hand, signs you’re not getting enough rest include waking up tired and groggy, feeling irritable throughout the day, experiencing excess hunger, having trouble with memory or concentration, or falling asleep during the day.   

Sleep quantity isn’t the only factor that matters, either. Sleep quality also makes a difference in health. According to research, poor sleep quality contributes to disease and poor health outcomes. So what defines “quality” sleep? This concept involves four components:

• Sleep efficiency (whether sleep makes you feel rested)
• Sleep latency (how long it takes to fall asleep) 
• Sleep duration (how long you stay asleep)
• Wake after sleep onset (periods of wakefulness during the night)

Health Benefits of Getting Enough Sleep

We all know how good it feels to wake up after a night of deep, refreshing sleep—and how bad it feels to arise after a night of staring at the clock. Besides making you groggy the next day, your sleep patterns can have a deeper impact on overall health. Here are five ways sufficient slumber boosts your well-being.

May Reduce the Risk of Chronic Disease

Quality sleep allows the body to not only rest but also to repair. As we sleep, our tissues and cells rebuild. It’s not surprising, then, that getting enough good rest can reduce the risk of numerous chronic diseases. Better, longer sleep has been linked to a lower likelihood of developing type 2 diabetes, cardiovascular disease, and cancer.  

Helps Maintain a Healthy Weight

Though physical activity may be the key to burning calories, there’s also a place for rest in your weight loss toolkit. A large body of research points to sleep’s role in weight management. 

One older study in the American Journal of Epidemiology, for example, tracked the sleep habits of over 68,000 women. Compared to those who slept seven hours per night, women who only slept five hours or less were 15% more likely to become obese over the course of 16 years. More recently, a 2017 study concluded that short sleep duration could be a driving force behind the obesity epidemic. 

Besides depriving your body of much-needed cell repair and inflammation reduction (both of which could contribute to weight gain), getting poor sleep may make you feel too tired to exercise. Plus, the appetite hormone ghrelin increases after just one night of sleep deprivation, making you more likely to overeat. 

Helps With Focus and Alertness

Got a big test or work presentation coming up? Conventional wisdom says to get enough sleep the night before—and research confirms this is good advice. A study revealed that poor sleep decreased the body’s ability to supply adequate blood flow to the brain. The result can be impaired cognitive performance.

Similarly, insufficient sleep has been associated with slower reaction times, inattentiveness, and poor responses to environmental signals—hence sleep deprivation’s potentially harmful effects on everyday activities like driving or work tasks. For optimal focus and alertness, be sure to get your Z’s.

May Prevent Dementia

In the short term, healthy sleep can help you maintain mental sharpness. But your long-term cognition may be affected, too. People who get more deep sleep are less likely to develop Alzheimer’s disease. This may be because deep, restorative sleep helps “clean” the brain of waste products including beta-amyloids that are thought to be involved in the development of Alzheimer's disease.

Boosts Mental Health

Sleep deprivation has a profound impact on the brain—sometimes, to the point of triggering symptoms of mental illness. Research shows that sleep problems can contribute to the onset or worsening of mental health disorders like depression, anxiety, and even suicidal ideation.

On the other hand, getting restful nightly sleep might help minimize such issues. A study in The Lancet Psychiatry found participants who received sleep treatment were less likely to report symptoms of depression, anxiety disorders, and psychosis.

How to Get Better Sleep

Want to make better sleep a reality? Focus on these strategies:

• Minimize stress. Stress is the enemy of sleep. Do what you can to process life’s stressors with tactics like mindfulness meditation, talking out problems with friends, or going to therapy.
• Eat right. Your diet has more impact on your sleep than you might realize. Avoid caffeine several hours before bedtime, or try a sleep-promoting snack before hitting the hay.
• Keep a consistent bedtime. Going to bed at the same time each night creates a rhythm your body expects.
• Get some exercise. Working out uses up energy, allowing you to feel tired when bedtime rolls around. For even better results, take your exercise outside. Research shows that vitamin D (the sunshine vitamin) is involved in sleep regulation.