Your body needs sleep, just as it needs air and food to function at its best. During sleep, your body heals itself and restores its chemical balance. Your brain forges new connections and helps memory retention. Without enough sleep, your brain and body systems won’t function normally. Stimulants like caffeine aren’t enough to override your body’s profound need for sleep. Behind the scenes, chronic sleep deprivation can interfere with your body’s internal systems and cause more than just the initial signs and symptoms listed above.