Did you know that sleeping one extra hour a night can lower your heart attack risk by 33 percent? Skimping on sleep raises risk for everything from high blood pressure to heart failure, stroke, diabetes, fatal heart disease, and even obesity.

One rocking-chair marathoner stayed awake for 18 days, 21 hours and 40 minutes, according to Australia’s National Sleep Project. Before sleep finally took over, the winner experienced hallucinations, paranoia, blurred vision and slurred speech.

It’s also possible to get too much of a good thing, since averaging more than nine hours of shuteye per night boosts heart disease risk, compared to people who slumber seven or eight hours. How much do you know about sleep? Here 10 little-known facts:

Find out how to wake up refreshed from a good night's sleep.

You think your pilot got enough sleep? Maybe not.

When the National Sleep Foundation surveyed airline pilots about sleepiness on the job, a distressing 23 percent admitted that lack of sleep affects their performance at least once a week, and 20 percent said they had made serious mistakes as a result. Even more train operators reported diminished job performance (26 percent), and 14 percent of truck drivers admitted having a near miss because they were sleepy. Half of the pilots, and 44 percent of truck drivers, said they never or rarely get enough sleep on work nights. Safe travels!

Dreams Can Occur During Any Phase of Sleep

Researchers once thought people only dream during REM (rapid-eye movement) sleep. They now believe we dream during other sleep phases as well.

While REM dreams tends to have elaborate, fantastical plots, non-REM dreams are more like thoughts, such as fretting over the idea that you lost your iPhone or misplaced your shoes. These obsessive thoughts tend to repeat over and over, without the vivid images we usually associate with dreams.

Pile your plate high with the right foods to beat fatigue.

Some People Have a Natural Alarm Clock

Researchers report that the signal that causes them to wake up when they want to is triggered by release of the stress hormone adrenocorticotrophin, in an unconscious anticipation of the stress of waking up.

Teens Need as Much Sleep as Toddlers

 If your teenager never wants to get up in the morning, it’s probably because she hasn’t slept long enough. Teens need about 10 hours of sleep on the average, the same as young children, while adults only need eight hours a night. Women may need to sleep an hour longer than men; not getting that extra hour might keep them tired and more prone to depression. People over 65 only need an average of six hours’ sleep.

The Brain Never Sleeps

Your body may be slumbering, but your brain never stops working. It stays busy, constantly instructing your systems to keep functioning—breathing, digesting, pumping blood and all the other tasks that keep you alive while you sleep.

Nighttime Violence Could Be a Brain Symptom

People who kick and punch while they dream are known as "violent sleepers." They have a 50 percent chance of developing a neurological disease such as dementia or Parkinson’s disease as they age. People who act out violent scenes in their dreams should consider neurological testing.

You May Be Able To Reset Your Body Clock in Just One Night

 If you’re traveling to a different time zone, or are switching to the night shift, it usually takes a week to adjust to the new schedule. However, you may be able to use your internal “food clock” to override your body clock, suggests a Harvard animal study. Here’s how: Stop eating 16 hours before you want to be awake. After you start eating again, your sleep/wake cycle resets as if it were the start of a new day.

Can’t sleep in a hot house?

Why is it that you love lying in the hot sun, but a hot bedroom is extremely uncomfortable? It’s because your sleep-wake cycle is closely connected to temperature.

In order to succumb to sleep, your core body heat must be in harmony with your skin temperature, and that works best between 64 and 86 degrees Fahrenheit. For older people, the range is much more narrow—between 73 and 77 degrees—which contributes to sleep disorders in that age group.

Sleep Deprivation Can Make You Stupid

 Researchers have found that a lack of sleep diminishes your attention and concentration, thereby affecting your problem solving abilities. Without adequate rest, you cannot learn well. It also keeps you from “consolidating” memories, so you cannot remember what you learned from day to day.

Lack of Sleep—or The Wrong Slumber Position—Gives You Wrinkles

 When you don’t get enough rest, your bodies release extra cortisol, the “stress hormone.” Too much cortisol breaks down the collagen in your skin—the substance that keeps it smooth and elastic.

Ironically, even an adequate amount beauty sleep can increase wrinkles—if you habitually snooze on your side or belly, with your face mashed into the pillow. These habits gradually etch “sleep lines” that eventually become permanent, according to a study published in Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery. Sleeping on your back, however, helps prevent or reverse the problem.