Why is Sleep Important?

Sleep is vital. We know sleep impacts, and is impacted by, nearly every organ system in the human body.

Sleep deprivation’s impacts on the brain

Sleep deprivation inhibits mental focus, memory, and learning. Not sleeping enough also raises your risk for developing certain psychiatric disorders including anxiety, depression, suicide, PTSD after trauma, substance abuse, dementia, and Alzheimer's disease. And it may even make you feel pain more acutely. On top of all that, it can make all the aforementioned mental health conditions more resistant to treatment.

Sleep deprivation’s impacts on the body

Sleep deprivation decreases your motor skills and can decrease average reaction times as much as alcohol. It wreaks havoc on your immune system, making you more susceptible to the common cold and flu. Insomnia also alters the balance between fat and muscle mass.

The damage to your health builds up over time. A researcher at Uppsala University in Sweden showed that sleep deprivation decreases your metabolism, increasing your likelihood of developing obesity.

Sleep deprivation’s impacts on the economy

One 2016 study showed sleep loss costs the US more than $400 billion each year and every year US workers miss 1.23 million days of work due to sleep deficits.

The benefits of sufficient sleep

As bad as not getting enough sleep is for your health and performance, getting enough sleep is a huge boon. A recent survey of 200 high-achievers showed that sleep was the most important measure of optimized mental performance. The New York Times lists a bevy of benefits, saying sleep “can measurably improve your memory, overall cognitive performance, ability to learn new information, receptivity to facial cues, mood, ability to handle problems, metabolism, risk for heart disease and immune system.” Getting enough sleep may help people read emotions, process external stimuli, and respond better to stress. It may also boost your memory.

What happens when we sleep

When you take in new information your brain fires a spark between your neurons called a synapse. Recent research on mice showed the sleeping brain saves strong and vital synapses and prunes weak ones. Researchers theorize that your brain saves memories that matter, like material that you expect to be on a test, or a conversation with a loved one while you sleep and discards less-important memories to save the caloric energy and space it takes to maintain them.

Sleep is also when your brain takes out the trash, so to speak. Just like you, every cell in your body takes in nutrients and poops out waste. The cell food comes in via your blood vessels, and the poop goes out via lymphatic vessels -- except in your brain, whose nooks and crannies are too tight. A recent study in rats showed their brains shrinking up to 60% during sleep so a separate union of slimmer janitors called cerebrospinal fluid can flow through.

These guys pick up toxic molecules such as beta-amyloid, which may contribute to neurodegenerative disorders like Alzheimer’s and Parkinson’s, and throw them out.

But it’s not just your brain that’s hard at work (sort of) while you’re asleep. While you’re out, your body sends blood from your brain to your muscles and secrets human growth hormone for healing and repair.