What happens to your body when you are sleep deprived?

When you are sleep deprived, your brain struggles to form new memories, concentrate, and make decisions, as the prefrontal cortex becomes less active. Reaction times slow significantly, similar to being intoxicated. Your body releases more cortisol, the stress hormone, which raises blood pressure and promotes inflammation. The immune system weakens, making you more vulnerable to illness. Hunger hormones become disrupted, with ghrelin increasing and leptin decreasing, which drives overeating and weight gain. Over time, chronic sleep deprivation raises the risk of heart disease, type 2 diabetes, and mental health disorders like depression and anxiety. Even a single night of poor sleep impairs cognitive function and emotional regulation noticeably.