Part 2
The more people worry, the less they sleep. And so the problem gets worse and worse.
In Britain, BUPA is a private international health and care service. They state that almost twenty five percent of the population suffers from sleep problems sometimes. They say that the problem gets worse with age. The problem affects nearly forty percent of women over the age of sixty-five. And it affects about thirty percent of men over sixty-five.
Scientists do not fully understand the purpose of sleep. But the effects of a lack of sleep give them a better understanding. They believe that the main purpose of sleep is to rest and repair the body. Doctors say that there are five levels of sleep. And these levels have different purposes. The deepest sleep is level five. It is called R. E. M. sleep - rapid, or quick eye movement. People who do not sleep for very long miss out on R. E. M sleep. And people who sleep very lightly also miss out on R. E. M sleep. Research shows that R. E. M sleep is very important. Without it, people often feel worried a lot. They do not feel at ease in their minds. In extreme cases the mind can play tricks on the person. They can hallucinate. They see things that are not there.
So what causes a lack of sleep?
There are many reasons why people find it difficult to sleep. Eating a large meal late at night can keep people awake. But not having enough food can also prevent sleep. Some people say that hot drinks help them. They have a warm sweet drink of milk before they go to bed. Milk and sugar both help the brain to make the chemical serotonin.
