Why do we need sleep?

We spend a third of our lives sleeping - or at least trying to - which is a huge portion of our existence.
There are many theories, but no one is exactly sure why we sleep.

Too little sleep can increase vulnerability to some diseases such as cancer.

What we do know is that sleep is crucial as we see when we don't get enough. Our concentration wanders, our memory is impaired and we feel groggy and irritable.

At one end of the scale, not sleeping enough can play havoc with how we look resulting in a pale complexion and dark circles under the eyes. At a far more serious level sleep deprivation can put ourselves and others in danger - for example if we're driving.

What is also known about sleep is that it is an active state, and it is thought that during slumber we rebuild and strengthen our muscles cells and immune system. Lack of rest can affect our health. Research has suggested for instance that a lack of sleep can be linked to an increased risk of obesity as it interferes with the hormones that regulate appetite. Other studies suggest that loo little sleep can increase vulnerability to some diseases such as cancer.

hmmmm very interesting Mandy