Insomnia is defined as difficulty getting to sleep, difficulty staying asleep or having non-refreshing sleep.
Having insomnia means that these difficulties happen three or more times a week, persist for at least a month and can affect our ability to function properly during the day.
Persistent insomnia can affect personal lives and performance at work, and delay recovery after your illness. It's also a major cause of depression.
Symptoms can include:
- lying awake for a long time before falling asleep
- waking up several times in the middle of the night
- waking up early and not being able to get back to sleep
- feeling tired and unrefreshed by sleep
- inability to concentrate during the day
- irritability due to lack of sleep
Most people with insomnia report having low energy during the daytime, but few of them feel sleepy, says Professor Kevin Morgan of Loughborough University's Sleep Research Centre.
"Instead, they stay in a wakened state, feeling tired, lethargic and without vitality," he says.
How much sleep do we need?
Most adults need between six and nine hours of sleep each night. Some people can feel perfectly rested with a lower amount.
Newborn babies can sleep for 16 hours a day, while school age children need an average of 10 hours. Most people over the age of 70 tend to be light sleepers and need less than six hours a night.
So how much sleep do we need? "Simply put, you need enough to make you refreshed and able to function efficiently the next day," says Professor Morgan. The number of hours depends completely on the individual.
Insomnia is more common among older people, and among women. Gender differences can probably be explained by differences in lifestyle, hormones, and perhaps the fact that fewer men report these problems.
"Factors such as periods, the menopause, pregnancy and child rearing can all contribute to insomnia," says Professor Morgan.
If you need help with your sleep, read sleeping pills and the alternatives for information on the different types of insomnia treatment.
Article provided by NHS Choices