Idiopathic Hypersomnia: Causes, Symptoms, And Diagnosis

There are many different forms of a sleep disorder known as hypersomnia, some of which haven’t been thoroughly investigated yet, and some have no known cause, such as idiopathic hypersomnia.

Idiopathic means a disorder in which nobody quite yet understands the reasoning behind why it flares up.

This can be frustrating for the sufferer, as not understanding your illness means you might not know how to treat it, and it can take longer to get under control.

One of the main symptoms of hypersomnia is excessive sleepiness during the day and the need to take naps, which can sometimes be hours long, yet still not ever feeling like you’ve had a refreshing sleep.

This is a very different condition from insomnia, in which the sufferer struggles to sleep at all at night, leaving them exhausted the following day.

Any sleep condition can negatively impact your general health and physical and mental well-being, and sleep disturbances can eventually affect your personal and professional life.

An Overview

An Overview

Idiopathic hypersomnia is a condition that often develops slowly over time, which means you may mistake it for general tiredness or put it down to stress or other aspects.

This can make it more challenging to diagnose and means that you will have to undergo several tests to rule out any other sleep disorders or underlying conditions.

Throughout this guide, I will be telling you how to spot the signs of idiopathic hypersomnia. I will also discuss possible causes and tell you how to get a correct diagnosis.

Hypersomnia Causes

Hypersomnia Causes

Idiopathic hypersomnia is a chronic condition caused by neurological complications, and it falls under the primary category of central sleep disorders called hypersomnolence. However, the two conditions are different.

Hypersomnia is a condition in which the sufferer must feel constantly tired throughout the day, no matter how much sleep they’ve had the day before.

It is sometimes confused with sleep seizing condition narcolepsy. However, once again, this is an entirely different condition. Hypersomnia is more of a lack of alertness than a sleep problem.

The idiopathic part of the condition technically means there is no cause, or at least the cause is not yet known or understood. After being diagnosed with hypersomnia, you get told that another illness or situation is causing it. This means you have secondary hypersomnia, therefore, not idiopathic.

Idiopathic Hypersomnia – Symptoms

Idiopathic Hypersomnia - Symptoms

There are many symptoms of idiopathic hypersomnia, some of which can often be caused by another condition or confused with other symptoms. However, if you’re experiencing all of these symptoms together, it’s highly likely that you’re suffering from idiopathic hypersomnia.

However, it’s important not to self-diagnose and to speak with a medical professional who may want you to undergo further tests, such as a sleep score test.

Here are some of the symptoms to look out for:

  • Excessive daytime sleepiness
  • Lack of concentration
  • Struggle to perform day-to-day tasks
  • Unable to wake up in the morning 
  • Feeling unrefreshed after a good sleep
  • Oversleeping 
  • Waking up feeling disorientated (sleep drunkenness)
  • Brain fog
  • Headaches
  • Depression 
  • Sensitive to heat
  • Hallucinations 
  • Sleep paralysis 
  • Low blood pressure 
  • Excessive sweating 

Diagnosing Idiopathic Hypersomnia

Diagnosing Idiopathic Hypersomnia

Some people may be putting off speaking to a specialist because they’re uncertain of what the testing process involves.

To test for idiopathic hypersomnia, firstly, your doctor or sleep specialist will want to ask you about your symptoms, lifestyle, and sleeping habits. From here, they will begin a process of elimination.

They might ask you to go away and keep a sleep diary for a couple of weeks, in which you will write down everything from your dietary habits to how long it takes you to get to sleep every night and how much exercise you do.

I advise you to do this before your initial doctor’s visit; it can help speed up diagnosing if you’ve already got a diary.

After this, they may want to take blood tests to look at possible causes, such as your iron levels and thyroid function, and ask you questions to find out if there may be something underlying such as depression or other psychological disorders.

If this is the case, they will treat these problems, and you should find that your sleep starts to regulate.

In the case that no underlying cause is determined, you may be referred to a sleep centre, where a more in-depth look at your circumstance can take place.

1. Epworth Sleep Scale (ESS)

Epworth Sleep Scale (ESS)

The first thing that will happen when you attend a sleep centre is that you’ll be asked a series of questions about your sleep hygiene, family history, and medical conditions.

They will also ask you whether you are self-medicating, over using substances. They will also try to determine whether you’re sleepy or just fatigued.

2. Sleep Study

After you have undergone the ESS, depending on the results, you may be asked to attend an overnight sleep study. This will depend on your preference and circumstance. Some of these take place at designated centre’s, and some can be done at home.

To participate in a sleep study, you might be required to pause any medication so that they don’t interfere with the results; this will include medications such as antidepressants. This is because they can suppress rapid eye movement and could overshadow a narcolepsy diagnosis.

I will advise you that these tests can be pretty uncomfortable, as you will be connected to many wires and sensors so that the specialists can accurately measure what happens while you’re asleep. However, it can be quite daunting for anyone suffering from anxiety, so discuss your concerns before the test takes place.

The results of your test will then help the physiologists narrow down the cause of the problem and come to a final diagnosis.

What The Test Looks For?

There are certain things that your sleep specialist will be looking for when conducting your sleep study. These include:

Another test that will take place at the centre is the multiple sleep latency test, which takes place during the day; this will look at how long it takes you to fall asleep and quickly enter REM sleep.



Once all the tests have taken place and all other causes have been ruled out or dealt with, it is possible that you will be diagnosed with idiopathic hypersomnia.

From here, you will be able to discuss with your sleep specialist the best way to treat your condition. Although there is no cure for idiopathic hypersomnia, there are some treatments, natural remedies, and lifestyle changes that you can put into place to help you live with the condition.

A Final Analysis

Various circumstances and medical disorders can bring on sleep conditions, such as hypersomnia. It could be something as simple as improving your sleep schedule, going to bed at the same time every night, or changing your diet.

It is always worth speaking to a medical professional before diagnosing yourself with an idiopathic sleep disorder.

The chances are there is an underlying reason that you’re experiencing difficulty sleeping, which means there will likely be a solution to your problem. But, getting accurate tests is vital.

Sarah Wagner

I'm Sarah Wagner, and I founded Sweet Island Dreams in 2022. It's a blog dedicated to helping people mental vacation virtually anytime they want. By providing information about the best sleep of your life, I help people drift away to paradise without ever having to leave their bed!