Insomnia is a broad term to describe a common sleep disorder. Insomnia refers to one of many conditions classified as sleep disorders.

Primary insomnia is not due to another medical or emotional condition and typically occurs for periods of at least one month. Whether some people are born with a greater chance of having insomnia is not clear yet. A number of life changes can trigger primary insomnia such as a major or long-lasting stress and emotional upset or other factors such as work schedules that disrupt your sleep routine.

Even after these causes go away, the insomnia might stay. Trouble sleeping may persist because of habits formed to deal with the lack of sleep. These habits include taking naps, worrying about sleep, or going to bed early.

Secondary insomnia is often a symptom of an emotional, neurological, medical disorder or another sleep disorder. The emotional disorders that can cause secondary insomnia includes depression, anxiety, and posttraumatic stress disorder. A number of other diseases and conditions can cause secondary insomnia such as arthritis and headache disorders, asthma and gastrointestinal disorders such as heartburn.

Sleep disorders, such as restless legs syndrome, also can cause secondary insomnia. In addition, secondary insomnia can be a side-effect of certain medicines or commonly used substances such as caffeine or other stimulants, tobacco or alcohol.

Lets look at the most common causes of insomnia. There are many possible causes of insomnia. Sometimes there is one main cause, but often several factors interacting together will cause a sleep disturbance. The causes of insomnia include: psychological causes, physical causes and temporary events or factors.

Psychological Causes
Anxiety, a condition in which individuals feel increased tension, apprehension, and feelings of helplessness, fear, worry, and uncertainty. This may be due to the effects that other people at work have on us, financial worries, concerns over relationships outside work or numerous other causes.

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 precipitating factor could be a traumatic event such as acute illness, injury or it could be a minor event, including extremes in weather, an exam, travelling, or trouble at work. In such cases, normal sleep almost always returns when the individual recovers from the event or becomes acclimated to the new situation.

Depression, a mood disturbance characterized by feelings of sadness, despair, and discouragement.

Physical Causes

Hormonal changes in women. These include premenstrual syndrome, menstruation, pregnancy, and menopause.

Medical conditions. These include allergies, arthritis, asthma, heart disease, high blood pressure and Parkinson's disease.

Temporary Events Or Factors

Adjustment sleep disorder. This form of sleeplessness is a reaction to change or stress. It may be caused by a traumatic event such as an illness or loss of a loved one, or a minor event such as a change in the weather or an argument with someone.

Air travel across time zones often causes insomnia. After long plane trips, one day of adjustment is usually needed for each time zone crossed. Travelling 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.