The personal costs cannot be estimated. They fight just to survive when it affects others around them. Sleeping disorders can tear their whole life apart. Although everyone needs sleep, we don't fully understand the reasons why we do sleep. We know that sleep deprivation can affect mental concentration and flexibility of response to situations and leads to a decreased ability to perform even simple repetitive tasks.
Some sleep disorders are potentially fatal, while others are merely annoying.
Some are lifelong, others are brief and non-recurring. However, there is more to the problem of sleep deprivation than the number of hours one sleeps. We need some periods of deep sleep, and some periods of active dreaming to get the kind of rest that restores our physical and mental well being. Many sleep disorders have the effect of waking the sleeper many times during the night, or not permitting him or her to achieve anything but the lightest sort of dozing sleep. Over the long term, inadequate or fragmented sleep can lead to a dangerous reduction in our ability to perform many tasks.