Groggy, grouchy, or unproductive in the morning? We’ve all been there. But what’s actually going on in your head when you don’t get enough sleep? This video from Ted Ed, written by educator Claudia Aguirre, looks at how sleep deprivation affects the brain. When we get tired, our bodies generate the hormones adenosine and melatonin, which relax our muscles, slow the heart rate, and gently lull us into a deep non-REM (rapid eye movement) sleep. It’s during this time that our bodies are replenished for the coming day. But when we don’t get enough sleep, learning, memory, mood, and reaction time all get worse. Sleep deprivation has been linked to hormonal imbalances, greater susceptibility to illness, and even in some cases death. It’s estimated that 30% of adults in the United States are regularly sleep deprived. Have trouble getting to sleep? Check out Mindful’s infographic: Seven Tips For Falling Asleep.