Upon falling asleep, thousands of neurons in the brain switch from waking to sleeping state, sending signals throughout the body. While the biological role of sleep still isn’t fully understood, research demonstrates that it reinforces the cardiovascular and immune systems and helps regulate metabolism.

Many biological processes happen during sleep: The brain stores new information and gets rid of toxic waste. Nerve cells communicate and reorganize, which supports healthy brain function. The body repairs cells, restores energy, and releases molecules like hormones and proteins. These processes are critical for our overall health.

Within a minute after falling asleep, notable changes start to affect both the brain and body. Body temperature drops, brain activity ramps down, and heart rate and respiration slow as well. Not surprisingly, the body’s energy expenditure is lower during sleep.

Sleep affects almost every type of tissue and system in the body – from the brain, heart, and lungs to metabolism, immune function, mood, and disease resistance.