Few things are as important as a good night’s sleep. The Centers for Disease Control and Prevention (CDC) says adults should get at least seven hours of sleep each night. This is because sleep allows your body to recharge and repair itself. Getting enough sleep can ward off a host of diseases and improve your mental health.

While You Sleep

As you sleep, your cortisol hormone level dips. It slowly increases through the night so you are alert in the morning. Your heart rate and breathing slow. Your blood pressure plunges, and your body temperature drops. Your body pumps out growth hormones and regulates your hunger hormones. And your brain cleans house.

You are not in a deep sleep most of the night. Rather, you cycle through sleep stages.. You wake up for a few seconds before each cycle begins again, even though you may not realize it. While your body rests during sleep, your brain remains active. It controls your body functions, such as breathing, even as it rejuvenates.

There are two sleep states. One is rapid eye movement, or REM. The other sleep state is nonrapid eye movement, or NREM. REM sleep is active sleep. You dream, your breathing and heart rate increase and become irregular, your muscles relax, and your eyes flutter. NREM sleep has four substages. It begins with drowsiness and advances to deep sleep. The restorative effects of sleep occur during deep NREM sleep. Yet, even during deep NREM sleep, your mind is active.

Benefits of Sleep

When you sleep, your brain recharges, your cells repair themselves, and your body releases important hormones that heal and rejuvenate. A restful night’s sleep helps keep your brain sharp, your immune system strong, your waistline trim and your skin healthy. It also lowers your risk for depression, diabetes, obesity, high blood pressure and heart disease.

While sleep by itself won’t help you shed unwanted pounds, restful nights can prevent weight gain. How, you wonder? Insufficient sleep increases the secretion of a hormone called ghrelin, which signals hunger. It also decreases the hormone leptin, which transmits the feeling of fullness. This imbalance may weaken your will to resist junk food, as your body will crave high-calorie, sugary foods to compensate.

Getting enough quality sleep protects your mental health, physical health, quality of life and safety. Sleep helps keep you happy, which bolsters all your relationships. It can prevent headaches. It lowers your risk of a car crash. A good night’s sleep even raises your pain threshold.

For these reasons, getting a good night’s sleep is just as important as eating right and routine exercise. Be sure you are giving your body and mind the rest they need to help you be at your best.

The CDC is an independent organization that provides health information you may find helpful.