January 2021 | Reviewed by: John Saito, MD and Seema Khosla, MD
What is idiopathic hypersomnia?
Idiopathic hypersomnia (IH) is an uncommon sleep disorder that is associated with excessive daytime sleepiness despite adequate quantity and normal quality of sleep at night.
If you have IH, you may sleep longer at night than the average person and may struggle to wake up. Once awake, you may seem confused or drunk (aka “sleep drunkenness”). You may take daytime naps that are several hours long and are often not refreshing. Your intense sleepiness often persists without need or cause and may be dangerous when you operate a vehicle or work equipment.
What are symptoms of idiopathic hypersomnia?
IH often develops in adolescence and is long lasting, though some instances of remission have been reported. IH can cause social and professional complications, including poor work or school performance, reduced earnings, and loss of employment.
Schoolwork, jobs, and relationships often suffer because of the excessive sleepiness. Someone with IH may appear to forget how to do simple activities or have difficulties with memory and brain fog.
Some people with this IH also experience these problems:
- Headaches
- Dizziness
- Cold hands and feet
- Depression symptoms
How to diagnose idiopathic hypersomnia?
Self test
Take the self-test below to see if you may have IH:
Are you very sleepy even though you sleep 8 to 10 hours or more nightly without interruption?
Has this been occurring daily for more than three months?
Are you very sleepy even after napping, in addition to getting enough sleep at night?
Are these naps unrefreshing?
If your answers to all these questions are yes, then you might have IH, but only a sleep doctor can help make the proper diagnosis.
Diagnosis
Diagnosing IH requires ruling out other common sleep disorders and other factors such as:
- Sleep apnea, restless legs syndrome, periodic limb movement disorder, or narcolepsy
- Other medical, neurological, or psychiatric conditions
- Use of alcohol, medications, or drug abuse
If you suspect you may have IH, contact a sleep doctor for consultation and diagnosis.
The doctor will ask you about your medical, neurological, and sleep symptoms. The doctor will ask about your medications, alcohol use, and family history. A thorough exam will be performed. You may need to complete a sleep diary to monitor your progress before and after treatment.
You will be asked to do a sleep study at night and testing the next day. The sleep study is called polysomnography. It charts your brain waves, heartbeat, muscle activity and breathing as you sleep overnight. It shows if there are other disorders that are causing or worsening your sleep problems.
Next, you will continue with daytime testing. This is called a Multiple Sleep Latency Test. This test is a series of daytime nap opportunities. You will be monitored to see how quickly you fall asleep during the day even though you had a full night of sleep the night before. People with IH tend to fall asleep during the day and are often unaware that they have fallen asleep.
How to treat idiopathic hypersomnia?
Since the causes of IH are currently unknown, treatment focuses on relieving the symptom of sleepiness.
Your doctor will decide what treatment is right for you, but the following are common parts of treatment programs:
- Keeping regular sleep times
- Taking prescribed medications when you need to be alert and active
- Avoiding driving if you feel sleepy
- Avoiding certain medications that may affect sleep and sleepiness
- Avoiding alcohol
- Treating all other sleep disorders that are present
- Treating any other medical or psychiatric conditions
Your doctor should monitor your progress as you undergo ongoing treatment. Make sure to tell your doctor right away if you have a significant side effect from a medication.
Another sleep study may be considered if symptoms of sleepiness increase significantly or if specific symptoms develop that suggest new or increased sleep abnormalities. This is a medical disorder that can be life-long although there are reports of people who get better and no longer need treatment. Research is ongoing to learn more about what causes IH. This will help to develop new treatment options.
Patient Support
- For additional idiopathic hypersomnia patient support contact Hypersomnia Foundation.
- The Assistance Fund offers a financial assistance program for people living with IH. The program helps eligible individuals pay for out-of-pocket medical expenses related to IH.