Insomnia is multifactorial, including physical factors such as the medicines we take, or the foods we eat and drink, and may often include psychological factors like stress or emotional loss.

There may also be an underlying medical condition which may
lead to chronic insomnia, such as:

•   chronic pain syndromes,
•   congestive heart failure,
•   acid-reflux (GERD),
•   sleep apnea,
•   asthma,
•   chronic obstructive pulmonary disease (COPD),
•   Parkinson's and Alzheimer's diseases, and
•   hyperthyroidism.

Short-term insomnia is often caused by recent events and unhappy experiences.   [4]

Another cause of insomnia is over-stimulation of the senses.

Researchers from the University of Helsinki report that media technology in the bedroom disrupts the sleep patterns of children.

They found that children with TVs, computers, video games, DVD players or mobile phones in their bedrooms slept considerably less than children without those devices in their bedrooms. [5], [6]

We also know that caffeine can disrupt our sleep patterns.

However, the “Ask the Pharmacist” website provides a LONG list of over-the-counter and prescription medications can ALSO cause insomnia:

Cold remedies, corticosteroids, statins, alpha blockers, SSRI antidepressants, ACE inhibitors, and a long list of other drugs.   [7]

From a medical standpoint, there are two types of insomnia:

Primary insomnia means that a person’s sleep problem is not directly caused by another health condition or problem.

Secondary insomnia means that a person is having sleep issues because of another health condition

such as asthma, depression, arthritis, cancer, or heartburn;

or a medication they are taking;

or a substance they are using (like alcohol or caffeine).

The hormonal swings of menopause may also disrupt sleep cycles. The newest addition to the list of causes is sleep apnea, first written about in 1965 by French and German scientists. [8]   PubMed currently lists over 58,000 articles just on sleep apnea. [9]