Insomnia is the most common sleep disorder, affecting about 10 percent of Americans, the American Sleep Association reports. Another 30 percent of Americans complain of excessive daytime sleepiness (EDS)—a condition that is so common that it is considered to be a major public health problem. EDS causes one out of five motor vehicle accidents, decreased work production, and many work-related injuries.

For most people with EDS, sleepiness is caused by not getting enough sleep. But for about 5 percent of us, it strikes even after a good night’s sleep. This condition is called hypersomnia, and it can be a major quality-of-life issue. Hypersomnia can be a symptom of another disease, or it can be a condition on its own.

Primary hypersomnia

When it is not caused by another condition, it is called primary hypersomnia. It is usually diagnosed between the ages of 17 and 24 and remains a long-term condition after diagnosis. There are three known types of primary hypersomnia: narcolepsy, idiopathic hypersomnia, and Kleine-Levin syndrome. The best known and most common cause is narcolepsy.

Narcolepsy is a brain disease caused by not having enough of a brain messenger (neurotransmitter) called hypocretin. This messenger helps control sleeping and waking cycles. About 75 percent of people with narcolepsy have a symptom not seen in other types of hypersomnia called cataplexy. Cataplexy is a complete and sudden loss of muscle tone that causes a person to collapse. It can be triggered by strong emotions. Another symptom of narcolepsy is vivid dreams or hallucinations and an inability to move just before falling asleep.

The most common treatment for narcolepsy is modafinil (Provigil). A drug called sodium oxybate is added to treat people with cataplexy.

Idiopathic primary hypersomnia is less common. The word idiopathic means unknown cause. When it was first diagnosed in the 1950s, it was called sleep drunkenness. People with this type of primary hypersomnia have normal brain hypocretin levels. Part of the cause may be abnormal genes passed down through families, since about 40 percent of people with this condition have a family history.

Idiopathic hypersomnia may also respond to stimulant drugs. The FDA recently approved another medication for this condition called Xywav, which includes the minerals calcium and magnesium along with the cataplexy drug sodium oxybate.

Kleine-Levin syndrome is very rare. The cause is unknown. People with this syndrome have periods of prolonged sleep lasting up to 20 hours. They only wake up to eat. When they wake up, they may be very hungry and may have strange personality changes. This condition has also been called hibernation or sleeping-beauty syndrome. Prolonged sleep periods usually last about 10 days and recur about every three months. Between attacks, these people return to normal sleep and behavior. Attacks may be triggered by drinking alcohol or by an infection, and they tend to become less frequent with older age.

Kleine-Levin syndrome does not have any approved drug treatment. Since the condition comes and goes, affected people may just have a doctor’s note allowing them to miss work or school during periods of prolonged sleep. The medication lithium may decrease the frequency of sleeping episodes for some people, and steroids may shorten the episodes.

Secondary hypersomnia

When hypersomnia is caused by another disease, such as sleep apnea, drug or alcohol abuse, hypothyroidism, Parkinson’s disease, a brain tumor, brain trauma, or depression, it’s called secondary hypersomnia. In these cases, hypersomnia can occur at any age and usually goes away when the underlying disease is treated. Until the cause can be controlled, people may be treated with modafinil.

General guidance

All people with hypersomnia can benefit from mental health support, exercise, planned naps, and avoiding stimulants like nicotine, caffeine, and alcohol. Sleep hygiene is also important. Sleep hygiene means setting regular hours for sleeping and waking, relaxing before sleeping, and keeping the bedroom dark and quiet.

Hypersomnia is a common problem that can be difficult to live with. It can even be dangerous if you have a sleep attack or cataplexy while driving or going down a staircase. It can interfere with your ability to function normally. Talk to your doctor if you have EDS or other symptoms of hypersomnia. Diagnosing the type of hypersomnia and getting on the best treatment can help control this condition and improve your quality of life.

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