Insomnia
Insomnia
Insomnia is probably the best known sleep disorder, and is defined as difficulty getting to sleep or maintaining sleep, or experiencing early morning wakening or non-restorative sleep despite adequate opportunities. A key feature is impaired daytime functioning.
Insomnia of less than three months’ duration – and typically only a few days or weeks – is regarded as short-term, whereas someone who experiences insomnia symptoms on at least three nights a week for three months or longer is regarded as having the chronic form of the disorder.
The prevalence of insomnia is higher in females, older adults and those with many long-term conditions, such as COPD, heart failure, chronic pain and mental health conditions. Around half of people with diagnosed insomnia have a psychiatric comorbidity.
As well as cognitive difficulties, such as impaired memory and concentration, quality of life and functioning may also deteriorate with insomnia, leading to an increased risk of road traffic accidents and falls (notably in older people), decreased productivity at work and increased absenteeism. Mental health complications include anxiety, depression and substance misuse, while medical complications include an increased risk of cardiovascular disease and type 2 diabetes.
The amount of sleep needed depends mainly on age:
- Babies sleep for around 17 hours a day, decreasing as they mature
- Older children need nine to 10 hours of sleep a night
- Most adults require about eight hours sleep a night – although this varies, with some getting by on as little as three hours. This is the same for older adults, although they will often only have one period of deep sleep during the night, soon after going to bed, after which they wake more easily while dreaming less.