What Is Catathrenia?

When a person loudly groans in their sleep

Catathrenia is a rare disorder that causes you to groan while you sleep. The sounds associated with catathrenia are often described as long moaning, humming, or cracking while breathing out. 

Woman sleeping in her bed, a light on the bedside table is on- stock photo

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Also known as nighttime groaning, this condition falls under the category of parasomnias, or disruptive sleep disorders. The cause is not well-understood, but research suggests catathrenia may be associated with an underlying breathing problem during sleep.

This article explains what catathrenia is, how it's diagnosed, and ways to treat it.

What Does Catathrenia Sound Like?

Catathrenia means a person makes a strange sound when they breathe out during sleep. People who hear these sounds often describe them as drawn-out moans or groans. It can also seem like you're humming and can even sound sad or gloomy.

The noises can be very loud, and they happen during the exhale (breath out). They are also linked to other breathing pattern changes.

For example, your breathing rate may slow, called bradypnea. You may also hold your breath briefly before you start to groan. Otherwise, there aren't any clear signs of trouble breathing.

Groaning sounds may happen in random clusters for five to 50 seconds each time.  You could have many groans that repeat for a few minutes up to an hour. These groans usually happen during rapid eye movement (REM) sleep. But they can also happen in stage 2 of non-REM sleep.

Usually, the person with catathrenia doesn't remember it. Without someone else noticing it, the sleep groaning can be overlooked.

Symptoms Associated With Catathrenia

A person with catathrenia may or may not have any other symptoms. When symptoms do occur, they can include:

  • Snoring
  • Fatigue
  • Decreased daytime alertness
  • Trouble with concentration or memory
  • Sore throat in the morning

Cause of Nighttime Groaning

The cause of catathrenia is unknown. However, limited research suggests catathrenia may be caused by dysfunctional neurons in the part of the brain that controls breathing, small upper airways, small jaws, or inspiratory flow limitation—when airflow stays constant even when you try to breath more.

Genetics may also play a role, as some people with catathrenia have a family member with the condition.


Catathrenia often starts in childhood. It affects young men more than women and can last for years. The exact cause is unknown. But psychological or psychiatric stress isn't the root of the issue.

Many times, catathrenia comes to medical attention when it's so loud that it disturbs other people. This can happen in dorms at college or in the military, or when sharing a bed with another person for the first time.

A sleep study called a polysomnogram can make an official diagnosis of catathrenia. A sleep center usually provides this test. The test will show changes in your breathing pattern and can record the groaning sounds.

Your healthcare provider may also examine your nose, mouth, and throat to identify any possible obstructions to breathing.

Catathrenia is different than other breathing problems and sleep disorders. Treatment options depend on the condition you have. Before you're diagnosed with catathrenia, a sleep specialist should rule out other conditions, including:


Treatments for catathrenia help some people, but not all. The treatments for the condition usually target the root cause. That said, since it's not clear what causes catathrenia or why it happens, it cn be hard to pick a treatment option that works.

Continuous Positive Airway Pressure (CPAP) Therapy

There's a possible relationship between catathrenia and sleep apnea, a condition where you stop breathing for brief periods while sleeping.

For that reason, continuous positive airway pressure (CPAP) can help some people. As you sleep, you wear a mask hooked up to a machine that delivers pressurized air to keep your airways open.

Not everyone with catathrenia responds to this treatment, however.

Oral Appliances

A customized mouthpiece can support the jaw in the forward position, helping to keep the airway open. This may help reduce catathrenia symptoms in some people.


If there is upper airway obstruction, surgical removal of the tonsils (tonsillectomy) or both the tonsils and the adenoids (adenotonsillectomy) may be another option to treat catathrenia.


Catathrenia is a sleep behavior that's usually harmless but can wake up other people. It happens when someone is sleeping and moans and groans as they breathe out. It's different than snoring, which happens when someone inhales, or breathes in.

A sleep specialist can help if you think you have catathrenia. They'll have you do a sleep study called a polysomnogram for an official diagnosis. From there, you can try different treatment options until you find one that works for you.

Frequently Asked Questions

  • Is catathrenia a sleep disorder?

    Yes. It’s a parasomnia, a sleep disorder with physical actions or experiences you can’t control and that interfere with your sleep. It can cause daytime sleepiness and disturb your sleep partner.

  • Is catathrenia dangerous?

    No. While groaning in your sleep may bother other people, it's usually harmless to you. However, it can lead to restless sleep or waking. In some cases, your breathing may be briefly disrupted.

  • Is groaning in your sleep hereditary?

    It can be. Researchers haven’t found the specific genes involved, but about 14% of people with catathrenia have a relative with the condition.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.