Glossary

hypersomnia

Hypersomnia is a type of sleep disorder that causes people to sleep excessive amounts (long sleep), have excessive daytime sleepiness, or both. Treatments for these disorders are often very similar, and current research shows that there may be significant overlap among some of them.

Hypersomnias are also called central disorders of hypersomnolence (CDH). They include:

• Idiopathic hypersomnia
• Narcolepsy types 1 and 2
• Kleine-Levin syndrome
• Hypersomnia and narcolepsy associated with other disorders

Hypersomnia refers to a type of sleep disorder. Hypersomnolence refers to the specific symptoms of long sleep or excessive daytime sleepiness (EDS). For example:

• People have or are diagnosed with a hypersomnia (a disorder).
  “My loved one has been diagnosed with a hypersomnia called narcolepsy type 2.”
• People experience hypersomnolence (a symptom).
  “My loved one has severe, daily hypersomnolence. They’re extremely sleepy almost all the time.”

To learn more, visit our web pages:

• Read about hypersomnia sleep disorders
• Diagnosis, classification, symptoms, and causes of hypersomnias (for doctors)