Insomnia or trouble sleeping is very common – about 30% to 40% of adults will experience insomnia in any given year. Insomnia is a symptom and is not a medical condition in itself. Rather, it's your body's way of telling you that something is not working right.
There are different types of insomnia. Some people have trouble falling asleep while others have trouble staying asleep or waking up too early. Also, sleep problems can be short-term, lasting a few days or weeks, or chronic, lasting for several months or more.
Insomnia is only considered a problem if it interferes with your life – if you wake feeling unrefreshed or find yourself dozing during the day. It is normal to sleep less as you age. If you're sleeping less than you did when you were younger but don't feel tired during the day, you should not worry.
Typical daily sleep requirements at different ages:
||Hours of sleep needed
||13 to 17|
||9 to 13
|10 years||10 to 11|
|16 to 65 years
||6 to 9
|over 65 years
||6 to 8|
The sleep of older people, as well as being shorter, is less deep. Only about 25% of the sleep of someone over 65 years is rapid eye movement (REM) sleep or stage IV (very deep) sleep, compared to over 50% in a young child. This probably means that older people dream less, since dreaming usually occurs during REM sleep.
As people get older, some get by with amazingly little sleep. Margaret Thatcher claimed to average 4 or fewer hours a night throughout her tenure as Prime Minister of Britain. Nevertheless, many people complain that a lack of sleep affects their daytime performance. At any given time, about 10% of the population consider themselves to have chronic insomnia. About half of us will suffer from insomnia at some point in our lives.
Insomnia usually has an underlying cause. Common causes of insomnia include:
- air travel, especially when traveling from west to east (jet lag)
- anxiety or depression
- medical conditions such as gastroesophageal reflux, prostate enlargement, Parkinson's disease, Alzheimer's disease, and stroke
- medications such as decongestants, stimulants (e.g., methylphenidate*) and some antidepressants
- nicotine, caffeine, and alcohol
- not being active enough during the day
- pain from arthritis or other medical conditions
- poor sleep habits
- shift work
- sleep problems such as sleep apnea
- stress caused by work, family life, death or illness of a family member or friend, or financial difficulties