Insomnia is more common in women and increases in the elderly, but is also commonly reported by the young.
Some people report thet they regularly sleep for a much shorter period without adverse effects.
Insomnia is not a trivial complaint. Sleep is important for both physical and psychological reasons and insufficient sleep can lead to fatigue, slower reaction times, irritability and other mood problems, and poor concentration. These in turn can affect work, relationships and quality of life. Each of these types of insomnia may occur in the absence of physical or mental ill health and this is called primary insomnia. Worry is a common and important factor in insomnia.