Insomnia is a sleep disorder in which an individual cannot fall asleep or stay asleep as long as is desired, resulting in poor quality of sleep. Sometimes referred to as sleeplessness, insomnia may often accompany other medical or psychiatric disorders. Individuals suffering from insomnia will often experience functional impairment during their waking hours.

There are several degrees of insomnia, and within there, three different types of insomnia have been categorized: transient; acute; and chronic.

Transient insomnia lasts anywhere from days to weeks. Transient insomnia may be likened to sleep deprivation.
Acute insomnia is the inability to gain the consistent level of sleep for a period of three weeks to six months.

Chronic insomnia will last for years at a time. People who suffer from chronic insomnia are at an increased risk of experiencing mental fatigue and hallucinations.

All types of insomnia may be brought on by an already existing medical disorder, changes in the sleep environment, changes to the hours during which one sleeps, severe depression, or even stress.

Insomnia more commonly affects women than men, and though it is not biased to age, individuals over the age of 60 are at higher risk. Age is not an excuse in homeopathy.