Different people need different amounts of sleep. Some people function well and are not tired after three or four hours’ sleep while others need eight hours per night. The amount of sleep needed by each person depends on their age, lifestyle, diet and environment. Everyone is different, but what matters the most is that the amount of sleep they get is enough for them.

 Why sleep is important?

Sleep is a state of consciousness which gives the body a vital opportunity to rest and build up strength.[1] A good night’s sleep is essential for good health. Sleep deprivation is associated with difficulty performing tasks such as planning, concentrating and movement. If it continues for long periods, lack of sleep can lead to excessive daytime sleepiness and affect the immune system.[2] There is also a link between impaired sleep and depression.[3]

The five stages of sleep[4]

Human sleep can be broken down into five recurring stages:

Stage 1, lasting five to 10 minutes, is a period of drowsiness in which the eyes are closed and activity levels are reduced by half.
Stage 2 is a period of light sleep consisting of waves of spontaneous muscle contraction and relaxation. In this stage, the heart rate slows and body temperature decreases in preparation for entering deep sleep.
Stages 3 and 4 are the deep sleep stages. Stage 4 is more intense than stage 3 and is repeated twice in each pattern.
Stage 5 (REM sleep) is characterised by rapid eye movement, accelerated heart and respiration rates and twitching muscles. Intense dreaming occurs during REM sleep
In a typical night’s sleep, a person may complete five cycles of the five stages of sleep.[4]

Sleep Stages[5]

Signs and symptoms of insomnia

Insomnia is defined as a persistent difficulty in falling or staying asleep, leading to disrupted daytime functioning.[5,6] Around a third of people in the UK suffer from bouts of insomnia, the signs and symptoms of which include:[1,6]

• Difficulty getting to sleep (also known as sleep onset insomnia)
• Frequent awakening in the night
• Waking up early in the morning and being unable to get back to sleep
• Feeling unrefreshed by sleep and still tired - often accompanied by problems with daily functioning, difficulty concentrating and irritability.

<PRACTICE POINT>
Ask your colleagues how many hours’ sleep they need to function properly the next day.