Idiopathic hypersomnia (IH) is a rare sleep disorder that causes extreme tiredness during the day for no clear reason. The word “idiopathic” means there’s no known cause, and “hypersomnia” means excessive sleep.
When you have idiopathic hypersomnia, the urge to sleep can happen anytime, even if you get plenty of sleep at night. You may not be able to stay awake and alert throughout the day. It can negatively affect your social life, work life, and home life.
Experts aren’t sure exactly how many people live with IH. They estimate the number is less than 200,000 people in the U.S.
Idiopathic Hypersomnia Types
Doctors don’t fully understand IH, and the way they define and diagnose it has changed over time. Symptoms can be different from person to person, and they can overlap with symptoms of other types of hypersomnia, such as narcolepsy.
While only one form of IH is officially recognized, many sleep experts think there are actually two types:
- Idiopathic hypersomnia with long sleep time
- Idiopathic hypersomnia without long sleep time
Symptoms are generally more serious with the long sleep time type.
Idiopathic Hypersomnia Causes
IH is a primary hypersomnia, which means it happens on its own. It isn’t triggered by other medical conditions.
Though the exact cause isn’t known, research has suggested the sleepiness may be due to:
A brain chemical abnormality. Some people with IH have too much of a small molecule in their cerebrospinal fluid (fluid that surrounds the brain). This molecule interacts with GABA, which is a brain chemical that promotes sleep.
A nervous system problem. Your autonomic nervous system controls things you don’t have to think about, like your heart rate and digestion. IH symptoms sometimes involve these types of body processes.
An autoimmune condition. This is when your body’s immune system attacks healthy cells by mistake. IH sometimes starts after you’ve fought off a viral infection.
Genes. About one-third of people with IH have a family history of the disorder.
There also seems to be a link between IH and certain mental health conditions, like depression, anxiety, and psychosis.
It’s possible that IH may have many causes, not just one.
Idiopathic Hypersomnia Symptoms
The main symptoms of idiopathic hypersomnia are:
- Excessive daytime sleepiness
- Trouble staying awake throughout the day
- Sleeping enough hours during the night but still feeling tired
- Taking long naps during the day
- Having a hard time waking up in the morning or after naps
- Feeling confused, groggy, or unrefreshed when waking up
People with IH typically sleep for at least 11 hours each day but still feel tired. Sometimes, the need to sleep can come on while you’re driving a car or at other dangerous times.
Some people with IH also experience:
- Anxiety or crankiness
- Low energy
- Restlessness
- Slowed thinking or speech
- Problems with memory, focus, or concentration
- Headaches
- Loss of appetite
- Dizziness or lightheadedness when standing
- Feeling hot or cold for no reason
- Hallucinations (seeing, hearing, or smelling things that aren’t there)
Idiopathic Hypersomnia Diagnosis
It can be hard to diagnose IH, and you might spend years trying to get to the root of your symptoms. Many things can cause you to be sleepy in the daytime, including more common sleep disorders.
You may get a diagnosis if:
- You’ve had symptoms of IH for at least three months.
- Your symptoms are severe and affect your daily life.
Your doctor will likely ask about your medical history, symptoms, sleeping habits, and medications. You may need to keep a sleep diary to log your patterns. Also, your doctor might ask you to wear a special sensor on your wrist to track your sleep-wake cycles for several weeks.
Usually a doctor makes the diagnosis of IH by ruling out other sleep disorders or other possible causes of your symptoms, such as medications, underactive thyroid, fibromyalgia, depression, and drug or alcohol use.
Questions to Ask Your Doctor
When you see your doctor, it’s a good idea to bring a list of questions.
You can ask:
- What could be the cause of my sleepiness?
- What treatments do you recommend?
- Do these treatments have side effects?
- What kind of results can I expect?
- What should I do if I feel sleepy while I drive?
- What else can I do to stay more alert during the day?
Finding Expert Care
You’ll probably need to see a doctor who specializes in sleep disorders to get your condition diagnosed correctly and find the best treatment. Ask your primary care doctor for a referral. Your insurance company can also point you to experts in your care network.
Several online resources can help you find a sleep specialist:
- The American Academy of Sleep Medicine maintains a directory of accredited sleep centers nationwide.
- The Hypersomnia Foundation has a tool that lets you search for sleep doctors in the U.S. and other countries.
If there’s a medical school in your area, check whether they have a sleep medicine program. You can also ask an IH support group for recommendations.
Idiopathic Hypersomnia Treatment
Since they don’t know the cause, doctors usually aim to treat the symptoms of IH.
The FDA has approved one drug specifically for treating IH in adults: Xywav, which contains lower-sodium oxybate. It’s a type of drug called a central nervous system (CNS) depressant, which slows brain activity. It’s thought to affect brain chemicals while you sleep, which may help with daytime symptoms. But Xywav has a high potential for misuse or abuse.
Other medications are prescribed off-label. That means they’re approved for treating a different condition but haven’t been proven to work on IH. Some that are used include:
Wakefulness-promoting drugs. Modafinil (Provigil) is a medication often prescribed for IH that you take during the day to feel more awake. Armodafinil (Nuvigil), pitolisant (Wakix), or solriamfetol (Sunosi) may also be prescribed.
Psychostimulants. More traditional stimulants including amphetamine, dextroamphetamine (Dexedrine, ProCentra, Zenzedi), and methylphenidate (Concerta, Daytrana, Methylin, Ritalin), can also be used, but you might become dependant on these.
Other depressants. Similar to Xywav are other drugs containing sodium oxybate (Lumryz, Xyrem). The muscle relaxer baclofen (Lioresal) might also improve your nighttime sleep.
Other meds. The antidepressant bupropion (Wellbutrin) may help you stay awake by increasing levels of the brain chemical dopamine. Drugs that block the action of the sleep-promoting brain chemical GABA include the antibiotic clarithromycin (Biaxin) and the sedative-reversing drug flumazenil (Romazicon).
Clinical trials are looking into a new class of drugs called orexin-2 agonists as possible treatments for IH. These drugs act like a brain chemical called orexin (or hypocretin) that helps you stay awake.
Your doctor might also suggest that you make lifestyle changes. For instance, you may want to keep a regular sleep schedule and limit caffeine and alcohol before bedtime.
A type of psychotherapy called cognitive behavioral therapy can help you cope with your symptoms and get better sleep at night.
Taking Care of Yourself
It can be hard to live with IH. Here are some ways to help you feel more alert:
- Go to bed at the same time each night.
- Keep your bedroom cool, dark, and quiet.
- Avoid alcohol, tobacco, caffeine, and exercise before bed.
- Be careful when you drive or operate equipment that can be dangerous.
- Avoid night shift work.
What to Expect
IH is a chronic illness without a cure. It’s not life-threatening, but IH can affect your well-being. You may find it hard to work, go to school, or have a social life. It can be dangerous to drive when you have IH, and you may not be able to have a job where you use machinery.
Treatments and certain lifestyle changes can help improve your symptoms, but many people don’t get complete relief.
How Your Condition Might Change Over Time
IH usually develops gradually. This means your symptoms might start out mild but slowly become more severe as time goes on.
You should expect to see your doctor about every six months to a year to discuss how well your medication is working and any changes to your symptoms. They may want you to take another sleep study or have other tests.
Caring for Your Emotional Health
Along with the physical toll it takes, IH can drain you emotionally, too. Your loved ones might not understand your constant need to sleep. It can be frustrating and even embarrassing to have to explain your condition to new people. A mental health professional can help you manage your feelings. Usually, your doctor or sleep specialist can refer you to someone who fits your needs.
Support groups are also an option for people with IH. These groups allow you to connect with other people who have the same condition.
Takeaways
Idiopathic hypersomnia is a rare sleep disorder that causes you to feel very tired during the day, even if you get a regular amount of sleep. There’s no single test that shows you have it, but a sleep specialist can diagnose it by tracking your sleep patterns and ruling out other causes of your symptoms. While IH doesn’t have a cure, medication can help manage your symptoms. You can help yourself by keeping a regular sleep schedule and taking care of your physical and mental health. Because IH is so rare, it may benefit you to connect with others who have it.
Idiopathic Hypersomnia FAQs
What triggers idiopathic hypersomnia?
Doctors don’t know what causes IH, but certain things may trigger the start of symptoms or make them worse. This includes a viral illness, a blow to the head, anesthesia, and a disruption to your normal sleep patterns.
Should you nap with idiopathic hypersomnia?
It depends on the person. You might find that a nap or two during the day helps you focus. But giving in to the urge to sleep might make you feel worse when you get up. Consider experimenting with naps of different lengths at different times of day.
Is hypersomnia a mental illness?
Like some other conditions that have a physical connection, sleep disorders are considered mental health conditions. Hypersomnolence disorder is listed as a sleep-wake disorder in the current edition of the Diagnostic and Statistical Manual of Mental Disorders.
Does idiopathic hypersomnia count as a disability?
It can. According to the Americans with Disabilities Act, a disability is anything that makes it very hard to do regular activities, including working and concentrating. In many cases, your employer will have to give you certain support to do your job. If your IH symptoms make it impossible for you to work, you may qualify for Social Security disability benefits.
