Sleep problems can be caused by various factors. Although causes might differ, the end result of all sleep disorders is that the body's natural cycle of slumber and daytime wakefulness is disrupted or exaggerated.
Factors that can cause sleep problems are:
- Physical (such as ulcers)
- Medical (such as asthma)
- Psychiatric (such as depression and anxiety disorders)
- Environmental (such as alcohol)
Short-term or acute insomnia can be caused by life stresses (such as job loss or change, death of a loved one, or moving), an illness, or environmental factors such as light, noise, or extreme temperatures.
Long-term or chronic insomnia (insomnia that occurs at least three nights a week for a month or longer) can be caused by factors such as depression, chronic stress, and pain or discomfort at night.
A common cause of chronic insomnia is a conditioned emotional response. Thoughts about the sleep problem (e.g., "What if I don’t fall asleep tonight?") and behaviors that develop around the sleep problem (e.g., sleeping in and napping, ruminating in bed) tend to maintain insomnia symptoms.
Other factors that can interfere with sleep
Researchers have found a genetic basis for narcolepsy, a neurological disorder of sleep regulation that affects the control of sleep and wakefulness.
Working the night shift
People who work at night often experience sleep disorders because they cannot sleep when they start to feel drowsy. Their activities run contrary to their "biological clocks."
Many medicines can interfere with sleep.
About half of all adults over the age of 65 have some sort of sleep disorder. It is not clear if it is a normal part of aging or a result of medicines that older people commonly use.