Sleep Disorders Patient Information Fact Sheet

What are sleep disorders?
There are many different types of sleep disorders, ranging from difficulty in getting to sleep or waking during the night and being unable to go back to sleep, to early wakening or poor quality sleep in general. Humans spend about a third of their lives asleep and it is estimated than one in four complain of poor sleeping patterns. Sleep problems are particularly common among the elderly population, although the elderly do require less sleep than younger adults.

The term insomnia is defined as a chronic (long-term) inability to fall asleep or to enjoy uninterrupted sleep. Other sleep disorders include narcolepsy (daytime sleepiness), obstructive sleep apnea (a disorder of breathing occurring during sleep), sleepwalking, nocturnal leg cramps, nightmares, sleep enuresis (bed wetting), snoring and sudden infant death syndrome (SIDS).

What causes sleep disorders?
Short-term sleep problems can be caused by external factors such as jet lag, bereavement, work stress, and exam stress, all of which will usually resolve with time. A partner who snores can also disturb normal sleep patterns. Pain and other physical reasons such as prostate problems or pregnancy (both of which cause the need to urinate during the night) can also cause poor sleep. In these cases the physical problem responsible for the sleep disturbance should be treated when possible.

Stress, anxiety, and depression can all cause difficulty in sleeping and early wakening, while stimulants such as caffeine and nicotine can delay the onset of sleep. Alcohol has both stimulant and sedative effects. Alcohol acts as a short-acting sedative and although it promotes sleep to begin with, as blood levels fall it starts to act as a stimulant and sleep is disrupted.

Being very overweight can cause obstructive sleep apnea. In people with this condition the upper airways become narrowed during sleep to the extent that the throat may become partially or completely blocked. If this occurs the person will fight for breath causing them to wake up. The awakening is often so brief that the person is unaware of it. However, they may be woken up to a thousand times a night which, in turn, causes daytime tiredness. Sleep apnea is most common in overweight men.

Nightmares and sleep walking are more common in children than in adults and are thought to be caused by an immaturity of the central nervous system. In adults, however, these events are more likely to be the result of psychological problems.

What are the problems associated with poor sleep?
There are many general effects of unsatisfactory sleep. For example, the person may wake feeling tired and irritable which can cause problems with relationships and in carrying out work to a satisfactory level. It is estimated that a quarter of all car accidents are caused by the driver falling asleep at the wheel.