Causes of Short-Term or Transient Insomnia:

A reaction to change or stress is one of the most common causes of short-term and transient insomnia. This condition is sometimes referred to as adjustment sleep disorder.

The trigger could be a major or traumatic event such as:

• An acute illness
• Injury or surgery
• The loss of a loved one
• Job loss

Temporary insomnia could also develop after a relatively minor event, including:

• Extremes in weather
• An exam
• Traveling
• Trouble at work

In most cases, normal sleep almost always returns when the condition resolves, the individual recovers from the event, or the person becomes used to the new situation. Treatment is needed if sleepiness interferes with functioning or if it continues for more than a few weeks. Individual responses to stress vary and some people may not experience insomnia at all, even during very stressful situations while others may suffer from insomnia in response to very mild stressors.

Female Hormonal Fluctuations

Fluctuations in female hormones play a major role in insomnia in women over their lifetimes. This insomnia is usually temporary.

• During Menstruation. Progesterone promotes sleep, and levels of this hormone plunge during menstruation, causing insomnia. (When they rise during ovulation, women may become sleepier than usual.)
• During Pregnancy. The effects of changes in progesterone levels in the first and last trimester can disrupt normal sleep patterns.
• Menopause. Insomnia can be a major problem in the first phases of menopause, when hormones are fluctuating intensely. Insomnia during this period may be due to different factors that occur. In some women, hot flashes, sweating, and a sense of anxiety can awaken women suddenly and frequently at night. In many cases, insomnia is temporary. Treating hot flashes may help resolve chronic insomnia.

Jet Lag

Air travel across time zones often causes insomnia. After long plane trips, 1 day of adjustment is usually needed for each time zone crossed. Traveling west to earlier times seems to be less traumatic than going east to a later time because it is easier to lengthen a circadian phase than to shorten it.

Effect of Light and Other Environmental Disruptions

Light, noise, and uncomfortable temperatures can cause sleeplessness. Depending on the time of day, too much or too little light can disrupt sleep.

• Excessive Light at Night. A person's biologic circadian clock is triggered by sunlight, and very bright artificial light maintains wakefulness.
• Insufficient Light during the Day. Insufficient exposure to light during the day, as occurs in some disabled elderly patients who rarely venture outside, may also be linked with sleep disturbances.

Other Causes of Short-Term or Transient Insomnia

Caffeine. Caffeine is a stimulant, which can interfere with falling asleep.

Nicotine. Nicotine is also a stimulant, but quitting smoking itself can lead to transient insomnia.

Partner's Sleep Habits. A partnerâ ' s sleep habits, including snoring, can impair oneâ ' s own sleep.

Medications. Insomnia is a side effect of many common medications, including over-the-counter preparations that contain caffeine. People who suspect their medications are causing them to lose sleep should check with their doctors or pharmacists.