Insomnia etiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Primary insomnia is sleeplessness that is not attributable to a medical or environmental cause. Secondary insomnia means that a person is having sleep problems because of something else, such as a health condition, an example of which would be generalized anxiety disorder.

Some of the most common causes of insomnia are, alphabetically;

• Circadian rhythm sleep disorders cause insomnia at some times of the day and excessive sleepiness at other times of the day. Common circadian rhythm sleep disorders include jet lag and delayed sleep phase syndrome. Jet lag is seen in people who travel through multiple time zones, as the time relative to the rising and falling of the sun no longer coincides with the body's internal concept of it. The insomnia experienced by shift workers is also a circadian rhythm sleep disorder.

• Dehydration causes stimulants, hormones, and cellular waste to build up in the blood rather than being flushed out, causing irritation, aches, and headaches (and hyperactivity in the case of stimulants). Drinking a cup or two of water can cause sleepiness within an hour or two.

• Lack of exercise - exercising four to five hours before bedtime can help you get to sleep easier. It has also been shown that people who are overweight or have high blood glucose levels have a harder time falling asleep

• Gastroesophageal Reflux Disease causes repeated awakenings during the night due to unpleasant sensations resulting from stomach acid flowing upward into the throat while asleep.

• Mania or Hypomania in bipolar disorder can cause difficulty falling asleep. A person going through a manic or hypomanic episode may feel a reduced need for sleep. Sleep deprivation can worsen a manic episode, or cause hypomania to develop into mania.

• Pain can produce insomnia and finding effective ways to treat pain can provide relief.

• Parasomnia includes a number of disorders of arousal or disruptive sleep events including nightmares, sleepwalking, violent behavior while sleeping, and REM behavior disorder, in which a person moves his/her physical body in response to events within his/her dreams. These conditions can often be treated successfully through medical intervention or through the use of a sleep specialist.

• Stimulants like caffeine, nicotine, sugar, certain medicines, or other pills/drugs

A common misperception is that the amount of sleep one requires decreases as he or she ages. The ability to sleep for long periods, rather than the need for sleep, appears to be lost as people get older. Some elderly insomniacs toss and turn in bed and occasionally fall off the bed at night, diminishing the amount of sleep they receive.^[1]

Insomnia is a common side-effect of some medications, and it can also be caused by stress, emotional upheaval, physical or mental illness, dietary allergy and poor sleep hygiene. Insomnia is a major symptom of mania in people with bipolar disorder, and it can also be a sign of hyper-thyroidism, depression, or other ailments with stimulating effects.

In addition, a rare genetic condition can cause a prion-based, permanent and eventually fatal form of insomnia called fatal familial insomnia.