Idiopathic Hypersomnia (IH)

What is Idiopathic Hypersomnia?

Idiopathic hypersomnia (IH) is a sleep disorder. If you suffer from hypersomnia, you may sleep for a normal amount of time at night, but also feel tired during the day. Even when you get 10 or more hours of sleep at night, you may continue to feel sleepy when you’re awake.

Doctors believe that IH sufferers produce too much of a molecule that impacts GABA, a hormone your body produces to promote sleep. The molecule interferes with how GABA works in the body and enhances its effects, leading to constant desire for sleep. What causes your body to overproduce the molecule is unknown.

What are the Symptoms of Idiopathic Hypersomnia?

If you have idiopathic hypersomnia (IH), you may sleep for an excessive time period “” at least 10 hours each day. When you’re awake, you may be groggy and have trouble functioning. Waking up is also difficult, and sufferers may not respond to alarm clocks.

People who have IH often have low levels of histamine in the brain, but there are no ways to specifically identify the condition. IH may have some connection to anxiety and depression, so if you suffer from those conditions, you may also have sleep issues.

Idiopathic Hypersomnia Causes

It isn’t fully understood what causes idiopathic hypersomnia (IH). However, some experts believe that it caused by the overproduction of a molecule which leads to sleepiness.

It isn’t clear exactly what this molecule is or why it is overproduced, but it is known that it reacts with GABA, a chemical in the brain which promotes sleep. Since excessive levels of the molecule are present in the body, the actions of GABA are enhanced and patients, therefore, feel unusually sleepy all the time, and rarely feel refreshed by long, deep sleep or daytime naps.

Much research is still being done to understand the cause of IH and decipher if there are any risk factors for the condition.

How is Idiopathic Hypersomnia Treated?

Many different issues may cause someone to suffer from idiopathic hypersomnia, treatment must be individually tailored to your needs. Often, treatment begins with a polysomnogram, or night-time sleep test, to see if there are easily correctable issues.

You may use light therapy or melatonin to reset your sleep cycles. Improved diet and exercise can help, as can eliminating alcohol and caffeine.

Your doctor may prescribe a stimulant that can help you feel less sleepy during the day. Some patients also benefit from antidepressant medications. Be sure to follow your medical professionals’ instructions so you do not become dependent on a stimulant drug.

In some cases, sleep apnea can mimic or contribute to IH symptoms. If this is the case, you may benefit from use of a CPAP machine to help you breathe properly while you sleep.

Idiopathic Hypersomnia Prevention

Since the cause of IH isn’t fully understood, there doesn’t appear to be an effective way to prevent the condition. However, individuals with the condition may be able to minimize their symptoms by making some simple lifestyle changes.

Firstly, adopting a strict sleep routine is vital. Individuals should aim to get a good amount of sleep – between six and eight hours – each night, and should try to go to bed and wake up at the same times each day. Naps may be necessary, but they should be scheduled at roughly the same time every day. It’s also important to avoid jobs which require night shifts or have shift patterns that frequently change, as this might interrupt the usual sleep routines which help to minimize IH symptoms.

People with IH should also avoid alcohol, since this can cause drowsiness and make the symptoms of IH worse. Medications which can cause drowsiness as a side effect, for example some allergy medications, should also be avoided.

To avoid injury caused by IH, it’s important to avoid driving or operating machinery when drowsy. For some patients, this may be all the time.

Last Reviewed:
September 21, 2016
Last Updated:
January 17, 2018