5. Sleepiness Is Depressing
Over time, lack of sleep and sleep disorders can contribute to the symptoms of depression. In a 2005 Sleep in America poll, people who were diagnosed with depression or anxiety were more likely to sleep less than six hours at night.
The most common sleep disorder, insomnia, has the strongest link to depression. In a 2007 study of 10,000 people, those with insomnia were five times as likely to develop depression as those without. In fact, insomnia is often one of the first symptoms of depression.
Insomnia and depression feed on each other. Sleep loss often aggravates the symptoms of depression, and depression can make it more difficult to fall asleep. On the positive side, treating sleep problems can help depression and its symptoms, and vice versa.
6. Lack of Sleep Ages Your Skin
Most people have experienced sallow skin and puffy eyes after a few nights of missed sleep. But it turns out that chronic sleep loss can lead to lackluster skin, fine lines, and dark circles under the eyes.
When you don’t get enough sleep, your body releases more of the stress hormone cortisol. In excess amounts, cortisol can break down skin collagen, the protein that keeps skin smooth and elastic.
Sleep loss also causes the body to release too little human growth hormone. When we’re young, human growth hormone promotes growth. As we age, it helps increase muscle mass, thicken skin, and strengthen bones.
“It’s during deep sleep -- what we call slow-wave sleep -- that growth hormone is released,” says sleep expert Phil Gehrman, PhD. “It seems to be part of normal tissue repair -- patching the wear and tear of the day.”
7. Sleepiness Makes You Forgetful
Trying to keep your memory sharp? Try getting plenty of sleep.
In 2009, American and French researchers determined that brain events called “sharp wave ripples” are responsible for consolidating memory. The ripples also transfer learned information from the hippocampus to the neocortex of the brain, where long-term memories are stored. Sharp wave ripples occur mostly during the deepest levels of sleep.