Discover what really goes on when you're catching zzzz's

 

 

A good night's slumber is vital not only for your mood. It also helps reduce the risk of heart attack and obesity.

So, have you ever wondered what sleep does for your body?

The eyes

As we move into deep sleep, rapid eye movement (or REM) occurs, with the eyes moving quickly for up to 30 minutes at a time, repeating every 90 minutes. Much of our dreaming happens during REM and despite our eyes moving intensely, our bodies are extremely relaxed – which helps us stay asleep.

The brain

Sleep is vital to give the cerebral cortex (the brain's "thinking" part) a rest. The brain's plasticity, which helps us learn and process, is maintained by sleep. A lack of sleep makes us feel we are working on autopilot. We feel irritable, less flexible in our thinking and less able to cope with the unexpected.

The mouth

During the course of the night, saliva flow is reduced. This results in a dry mouth in the morning. One in 10 adults unconsciously grind their teeth at night, which is known as bruxism. This reaction is thought to be triggered by stress.

Heart and blood

While sleeping, your heart rate and blood pressure fall by about 10 per cent. People who sleep seven to eight hours a night have the lowest rates of heart disease.
 

Hormones

Sleep releases growth hormones, which boost muscle mass and repair cells and tissues. Lack of sleep can lead to obesity because of an imbalance in the hormones that regulate appetite. A good sleep lowers levels of ghrelin, which triggers appetite, and raises the levels of leptin, which tells your body it's full.

Immune system

A lack of quality sleep can disturb the ability of the immune system to fight infection, leaving the body vulnerable to viruses that cause colds and flu. Having less than seven hours' sleep depletes the body's ability to produce antibodies.

Skin

The fresh face we see after a good night's sleep is sometimes only temporary, and may be caused by water accumulating under the skin. Water flattens out wrinkles, but drains away an hour after we get up, making wrinkles reappear. Sleep also gives the skin a chance to be repaired by nocturnal growth hormones.

Body temperature

Just before we go to sleep our core body temperature drops, to ensure a good night's sleep. Insomniacs tend to have a warmer core body temperature than normal sleepers just before bed, which means they struggle to fall asleep.