Primary Hypersomnia

The main feature of Primary Hypersomnia is prolonged sleepiness for a minimum of 1 month as shown either by abnormal sleeping occurring almost every day.

The excessive sleepiness should be enough to trigger substantial distress or impairment in social, occupational, or other essential areas of functioning.

The abnormal sleepiness doesn't happen exclusively throughout the course of an additional sleep condition or mental disorder and isn't because of the direct physiological results of a substance or a general medical condition.

During a Typical Episode

In people with Primary Hypersomnia, the duration of the main sleep episode might be anywhere from 8 to 12 hours and is frequently followed by difficulty waking up in the mornings. Excessive sleepiness through out regular waking hours takes the form of intentional naps or unplanned moments of sleep.

Daytime naps tend to be fairly lengthy, typically lasting an hour and sometimes more. They are often unrefreshing, and usually don't result in improved alertness. Individuals typically experience chronic sleepiness over a period of time, rather than a sudden sleep episode.

Diagnostic criteria summarized from:

American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders, fourth edition. Washington, DC: American Psychiatric Association.