Quality shuteye is some of the best medicine available. It leads to more energy, helps you handle stress, and improves overall wellbeing. Your system also benefits in countless little-known yet important ways when you get the seven to eight hours nightly that experts recommend. Sleep is your body’s time to heal, recharge, and restore itself. Skimp on it, it that sleep debt affects every body function, from your memory to your mood to the number of sick days you take and even your risk for a heart attack, says Shalini Paruthi, M.D., a sleep specialist and spokesperson for the American Academy of Sleep Medicine. In case you need more convincing, here are the 11 biggest ways sleep gives your body a major assist.