How much we sleep and how much sleep we need changes as we age6.
Babies to Teenagers
As babies we need as much as 19 hours every day, with sleep divided into chunks of three or four hours. By the time we’re starting school we need between 10 to 12 hours per night. However, research amongst teenagers’ sleep habits shows their tendency to reduce the number of hours that they sleep, go to bed later and have an increased level of sleepiness during the day. Teenagers probably need more sleep at this stage in their lives but many factors can affect their sleeping patterns: puberty can cause sleepiness during the day even if there are no problems falling asleep at night. Circadian rhythm changes can also impact sleep patterns. Furthermore, environmental or societal factors such as teenagers becoming less reliant upon their parents to set bed times or being involved in part-time work can upset their natural rhythm of sleep.
At around 20 years of age we sleep for between seven and eight hours per night, but there is considerable variation between individuals as to what is enough sleep. A healthy young adult will spend half the night in stage two non-rapid eye movement (NREM) sleep and a quarter in rapid eye movement (REM) sleep.
Middle Age to Retirement
Once we pass through middle age our sleeping patterns begin to change and by the time we’re elderly, we feel sleepier earlier in the evening than we used to and wake earlier in the morning. We’re also much more likely to experience interrupted sleep during the night and feel the need for naps during daytime which in turn can harm Quality of Sleep at night.
What affects our aging sleep pattern?
Melatonin is an important hormone which regulates our natural time clock, that controls the circadian sleep-wake rhythm. Melatonin production changes during the day and is affected by light; by raising levels of melatonin as night falls the Circadian clock tells your brain and body that it is dark and time to sleep1 2. Melatonin continues to deliver the night message to the body throughout the night period to ensure proper control of homeostatic systems such as sleep and blood pressure rhythms.
As people age, the ability of the body to produce melatonin is reduced, making them prone to sleep problems or insomnia as well as difficulty to keep blood pressure low during the night because the brain is in a “wake” state3.Fig. 1
Sleep problems in the elderly
Unfortunately, people are more likely to have sleep problems as they age4 5.
Disturbed sleep can really affect your Quality of Life because of how it makes you feel the next day and because of how your body is able to maintain optimal functioning. If your sleep is badly disrupted you may not be as awake as normal and your reaction times could be slower. You could find that your balance is not as good as it should be, furthermore, poor sleep can even affect your cognitive function (mental processing) whereby you experience poorer memory control than people your age who have had a good night’s sleep.
In the elderly these problems can worsen the normal decline in cognitive functioning that is part of aging. They can also affect family life and relationships, as tired people can be grumpy. Insomnia can also make people feel anxious and depressed.