What happens to our body when we sleep?
Even though sleep is such a common phenomena, not all scientists agree the real purpose of sleep. Following are some of the theories behind why we sleep. (Additionally read below about the different stages of sleep)

Brain recharging:
This is a way to give rest to our brain, although our brain continuously works even when we sleeps, it works at a much lower power. This helps to repair neurons, archive memories and reorganize.

Body relaxing:
When we sleep our metabolism and energy consumption goes down, this gives most of our organs to work in a relaxed mode. Even our blood pressure and heart rate falls when we sleep. Our body also gets a chance to repair muscles and replace dead cells more easily. Certain kind of hormones are released to relax the body.

Adaptive theory:
This is like the Charles Darwin theory of evolution, according to it sleep improves an animal's likelihood of survival. Depending on the type of creature, everyone has a different sleeping pattern like nocturnal species sleep in the day and stay awake in the night because their food is most available in the night.

Are You Getting Your Beauty Sleep?
You know how important good nutrition and exercise are for your health and beauty, but do you know sleep is crucial too? When you doze you're getting more than rest. Sleep researchers say your body is healing and repairing itself. For this reason, dermatologists often suggest using your most "active" skin creams before bed. To avoid puffy, bloodshot eyes, dark under-eye circles and a pale washed-out complexion -- and for peak alertness and energy -- experts say you need eight hours of sleep a night.

Here are some tips from the Sleep Disorders Institute at New York's St. Luke's Roosevelt hospital to help you get the sleep you need:

•  Exercise every day. Even 20 minutes of walking can help keep stress hormones from interfering with your sleep. Avoid large meals just before    bedtime. An active digestive system can disrupt sleep.

•  Minimize light, noise and temperature extremes, your bedroom should be comfortably cool, about 68 degrees.

•  Don't read, watch television or work in bed. Use the bed only to sleep. This helps prevent you from developing sleep disorders. Avoid    caffeine, nicotine or other stimulants within four hours of bedtime.

The next time you want to remember what you were taught, take a nap and dream about it. You may just remember it better. That is what scientists at the Center for Sleep and Cognition at Beth Israel Deaconess Medical Center in Boston, Massachusetts had to say after a new study. Robert Stickgold the lead author confirmed that a nap would improve the chances of your remembering stuff if you dream it.

"When you dream, your brain is trying to look at connections that you might not think of or notice when [you're] awake," said Robert Stickgold, "In the dream...the brain tries to figure out what's important and what it should keep or dump because it's of no value."