The different types of insomnia can be based on the causes, as well as how long the condition lasts.
Common types that are based on specific causes include:
- Primary insomnia
- Secondary insomnia.
Types that are based on how long it lasts and how often it occurs include:
- Short-term insomnia (including acute and transient)
- Chronic insomnia.
There are many insomnia causes. Some are more likely to result in short-term insomnia, while others are more likely to cause chronic insomnia.
Short-term insomnia generally occurs in people who are temporarily experiencing one or more of the following:
- Environmental noise
- Extreme temperatures
- Change in the surrounding environment
- Sleep/wake schedule problems, such as those due to jet lag
- Side effects of medication, particularly medications that treat:
Chronic insomnia is more complex and often results from a combination of factors, including underlying physical or mental disorders. One of the most common causes of this type is depression.
Other medical conditions that can cause it include:
- Kidney disease
- Parkinson's disease
- Sleep apnea
- Restless legs syndrome
- Heart failure
Chronic insomnia may also be due to behavioral factors, including:
- Drinking alcohol before bedtime
- Ingesting excessive amounts of caffeine
- Excessive napping in the afternoon or evening
- Chronic stress
- Expecting to have difficulty sleeping and worrying about it
- Smoking cigarettes before bedtime
- Irregular or continually disrupted sleep/wake schedules, as may occur with shift work.
In 20 percent of chronic cases, the cause is unknown. This is known as primary insomnia.