What happens to your body when you sleep

    What happens to your body when you sleep

  • 1 Your brain stays active

    Studies have shown that the brain remains active while a person sleeps. The brain activity is usually lower than the activity level when a person is awake, but when a person starts dreaming the activity becomes higher than when the person is awake.

  • 2 Waste removal

    An experiment on mice suggested that the brain of humans gets more active with the waste cleaning process as we are asleep. During sleep, the body gets rid of toxins and harmful substances.

  • 3 Reinforcing memories

    According to one theory, the purpose of dreams is to reinforce memories and store them properly. During sleep, the brain processes memory events and stores them properly.

  • 4 Physiological processes slow down

    Physiological processes, including breathing and heart rate, slow down when the person sleeps. The major organs relax and the muscles become less tense.

  • 5 Blood pressure is lowered

    As a result of the relaxation of organs and vital processes, the blood pressure gets lowered while the person is asleep. See how sleep affects health.

  • 6 The body temperature goes down

    When a person sleeps, his body temperature goes down. This is why cold weather can help the person sleep, as it imitates what the body does. See why exercising in cold temperatures is a bad idea.

  • 7 You lose weight

    As you perspire humid air while sleeping, your body loses some weight. This happens while you are awake as well, but the fact that you are eating makes it seem like you are not losing weight.

  • 8 You get taller

    The Spinal Disks re-hydrate while you are asleep and expand in size. This results in a little height increase. 

  • 9 Your muscles are temporarily paralyzed

    The body paralyzes the muscles during sleep in order to prevent you from doing any knee-jerk movement while you are dreaming. This temporary paralysis helps ensure your safety. See how to get a good night sleep.

  • 10 Your eyes move randomly

    During sleep the body goes through 90-minute-cycles called REM cycles. Dreams happen during REM cycles, rapid eye movement cycles. During REM, the eyes keep moving randomly and fast in different directions.

  • 11 Growth hormone production increases

    When you are asleep, you are in a fasting state. This fasting state forces the body to release more growth hormone to allow fat cells to release energy. This results in increased collagen production as well. See signs of Growth hormone deficiency.

  • 12 Cells get repaired

    During sleep, the body starts repairing damaged cells and tissues.

  • 13 The immune system gets stronger

    Studies have shown that When you sleep your immune system becomes stronger. This is why we feel better after sleeping well. See why over sleeping is bad for you.

  • 14 The sense of hearing remains active

    During sleep, the sense of hearing remains active. This is why you might wake up on a certain sound and this is also why external sounds can be part of our dreams. See why we dream in symbols.

  • 15 The skin's metabolic rate speeds up

    During sleep, the body increases the repair speed of skin cells and this is why deep sleep can help in making a person look more attractive.

  • 16 Digestive system slows down

    Because the body needs less energy while a person is sleeping, the digestive system slows down greatly. This is why eating heavy meals at night is not recommended, as the body won't be able to digest them properly.