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/ Sleep Disorders / Sleep-Related Breathing Disorders

Catathrenia: Why Do I Moan in My Sleep?

Updated October 16, 2025

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Table of Contents

What Is Catathrenia?
Catathrenia Symptoms
Catathrenia Causes
Diagnosing Catathrenia
Catathrenia Treatment
When to Talk to Your Doctor

Key Takeaways

Definition: Catathrenia is a rare sleep-related breathing disorder that leads people to moan or groan loudly in their sleep.
Symptoms: People with the disorder inhale, stop breathing, then moan loudly as they exhale.
Causes: Experts aren’t sure if catathrenia is caused by small craniofacial structures, abnormal receptors in the brain, or something else.
Treatment: Using a CPAP machine or an oral appliance or undergoing a tonsilectomy may help decrease instances of moaning or groaning.

Some people make quiet, rhythmic groaning sounds as they breathe out during sleep. This phenomenon is known as catathrenia, or sleep-related groaning. Catathrenia isn’t dangerous, but it can be disruptive to sleep partners and potentially embarrassing for those who have it.

Though researchers don’t know exactly what causes catathrenia, they have pinpointed effective diagnostic methods and treatment strategies that can decrease or eliminate nighttime groaning. With the right evaluation and care, most people with catathrenia can manage their symptoms and sleep more peacefully.

Is Your Nighttime Groaning a Health Risk?

Answer three questions to understand if your nighttime groaning is a concern you should worry about.

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What Is Catathrenia?

Catathrenia is a rare sleep-related breathing disorder that causes you to groan or moan loudly in your sleep Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source as you exhale.

These sounds usually last between two and 49 seconds and primarily occur during REM sleep Trusted Source Sleep View Source , but can also happen during non-REM sleep.You may be unaware that you’re making any sounds.

Previously, catathrenia was classified by the International Classification of Sleep Disorders as a parasomnia. Parasomnias are unusual or undesirable behaviors Trusted Source Merck Manual First published in 1899 as a small reference book for physicians and pharmacists, the Manual grew in size and scope to become one of the most widely used comprehensive medical resources for professionals and consumers. View Source that happen while falling asleep, during sleep, or as you wake up. Unlike the parasomnia sleep talking, catathrenia does not involve talking or gibberish during sleep.

Catathrenia Symptoms

The primary symptom of catathrenia is an almost nightly moaning or groaning sound during sleep that the sleeper does not realize they’re making.

Both adults and children can experience catathrenia. Typically, family members or sleep partners are disturbed by the sound, which prompts the person with nighttime groaning to seek treatment.

Given the low number of cases studied, experts have a limited understanding of other symptoms associated with the disorder. In some case studies, combinations of the following symptoms have accompanied nighttime groaning:

Snoring
Dry mouth
Mouth breathing
Sleep disruption
Fatigue
Morning grogginess
Morning headache
Trouble concentrating

What Does Catathrenia Sound Like?

The sound is often monotone and may be perceived as sullen, gloomy, or sexual in nature Trusted Source Sleep View Source . The groaning happens when you exhale and stops when you inhale. Some people also make humming, cracking, or sighing sounds.

Catathrenia sounds typically happen during REM sleep, and they can last just a few seconds or as long as almost one minute. Trusted Source Sleep Medicine View Source These sounds can be quite noisy too, with decibel levels up to 75, or about as loud as a vacuum.

Catathrenia Causes

The exact number of people who have catathrenia is unclear. Researchers have reported that between 0.17% and 0.4% of people with sleep problems Trusted Source Journal of Clinical Sleep Medicine (JCSM) JCSM is the official, peer-reviewed journal of the American Academy of Sleep Medicine. View Source experience the unusual disorder.

Experts haven’t yet determined why certain people moan in their sleep. Existing research is limited and debated among scientists. What researchers do agree on, is that the groaning and moaning sounds that people with catathrenia make are not snoring and are a result of abnormal breathing patterns.

In a small study of women with catathrenia, experts found that the participants all had smaller-than-average jaws and narrow upper airways, which limited how much air they could inhale. Trusted Source Sleep View Source These researchers hypothesize that because participants have a hard time getting enough air when they inhale, they groan or moan forcefully when exhaling in order to fully clear their airways between breaths.

Another group of researchers disagree that airway issues are the cause of catathrenia, and instead suggest that it could be related to miscommunications between the brain receptors that control breathing. Trusted Source Sleep View Source

Though experts disagree on catathrenia’s root causes, they do agree that people with it breathe in, then hold their breath, and exhale while using their larynx to moan or groan.

Diagnosing Catathrenia

Sleeping partners or caregivers are often the first people to notice that someone has catathrenia. Taking audio recordings of the sleeper while they’re groaning or moaning can help physicians make a diagnosis. If you or a partner suspect catathrenia, an in-person polysomnography, or sleep study, can help.

Catathrenia is easy to misdiagnose as central sleep apnea, because the two disorders show similar sleep study results. Doing an in-person study rather than an at-home sleep apnea test can help because it allows technicians and physicians to hear and observe any moaning or groaning, which can differentiate a catathrenia diagnosis from central sleep apnea diagnosis.

Catathrenia Treatment

A number of treatments have been successful in limiting or eliminating nighttime groaning. These treatments range from the use of medical devices to surgeries. People with catathrenia often use multiple forms of treatment to address symptoms of the disorder.

Continuous Positive Airway Pressure (CPAP) Therapy

A CPAP machine is a common form of treatment for obstructive sleep apnea. The medical device delivers pressurized air Trusted Source Medline Plus MedlinePlus is an online health information resource for patients and their families and friends. View Source through a mask you wear as you sleep. This type of therapy ensures the windpipe stays open as you sleep and prevents the airway from collapsing.

Small studies have shown that CPAP is an effective therapy for people with nighttime groaning. Trusted Source Revista Portuguesa de Pneumologia View Source The use of CPAP in these cases has also been shown to improve alertness in the daytime.

Oral Appliances

Oral appliances used to treat snoring and obstructive sleep apnea can also be an effective treatment for catathrenia. Trusted Source Journal of Clinical Sleep Medicine (JCSM) JCSM is the official, peer-reviewed journal of the American Academy of Sleep Medicine. View Source These appliances are worn only at night Trusted Source American Academy of Dental Sleep Medicine (AADSM) AADSM is the leading national organization representing dentists who treat sleep-disordered breathing, which includes obstructive sleep apnea (OSA) and snoring. View Source and fit like a retainer. The purpose of the oral appliance is to keep the upper airway open.

Tonsillectomy and Adenotonsillectomy

Removal of the tonsils (tonsillectomy) or removal of both the tonsils and the adenoids (adenotonsillectomy) provides another way to treat nighttime groaning. Several case studies have shown that these surgeries reduce nighttime groaning symptoms. Researchers note that the treatment is especially effective when a device such as a CPAP machine or oral appliance is also used.

Sleep Hygiene

To achieve better sleep overall, improve sleep hygiene. Proper sleep hygiene includes Trusted Source Medline Plus MedlinePlus is an online health information resource for patients and their families and friends. View Source :

Keeping a regular sleep-wake schedule, even on the weekends
Creating a sleep-friendly environment that minimizes light and noise
Engaging in relaxation before bedtime, such as taking a bath or reading a book
Exercising during the day
Avoiding caffeine in the afternoon and evening hours
Limiting alcohol intake
Avoiding the use of electronics Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source in the hours before going to sleep

Alternatively, if the groaning is only a mild disturbance to your bed partner or family, consider investing in sound-reducing accessories. For example, a white noise machine can cover the sound of groans. Sleep partners could also wear earplugs or noise-canceling headphones.

When to Talk to Your Doctor

Often, people with nighttime groaning don’t realize they have the disorder. Instead, a family member or sleep partner may inform them about the sounds they make. If you make nighttime sounds that are disturbing to those around you or you experience other symptoms such as disrupted sleep and fatigue, contact your doctor.

If possible, record your symptoms and observations of the groaning sounds. These notes can give your healthcare provider a clearer picture of your experiences. Your doctor can then rule out asthma or sleep disorders, such as sleep talking and snoring.

Diagnosis of catathrenia is typically done with polysomnography, or a sleep test. If you have nighttime groaning, your sleep test may indicate abnormal breathing disturbances and limited airflow. Your doctor may also do a physical exam of your head, neck, jaw, and tonsils to identify possible markers associated with nighttime groaning.

Frequently Asked Questions

Is catathrenia dangerous?

Catathrenia itself isn’t dangerous, but it can affect sleep quality and coincide with side effects like fatigue, daytime drowsiness, and decreased concentration. People with catathrenia also report that it can cause stress and embarrassment, especially when sleeping near a partner or roommate.

Can catathrenia go away?

Catathrenia is considered a chronic sleep-related breathing disorder that’s unlikely to go away on its own. It’s rare and experts haven’t spent as much time studying it as they have other disorders like sleep apnea. However, researchers have identified some treatments for addressing catathrenia symptoms.

Studies suggest that regular CPAP use can decrease or eliminate groaning symptoms. Sleeping with oral appliances like mandibular advancement devices may change your jaw’s position enough to decrease instances of groaning.

How is catathrenia different than snoring?

Catathrenia produces a moaning or groaning sound rather than a snoring sound. Snoring sounds are produced in the throat and they happen on inhalation when air moves by the throat’s soft tissues. Catathrenia’s moaning noises come from the larynx and usually happen when exhaling. While both sounds can be disruptive to partners, catathrenia sounds are more unusual and the disorder is quite rare.

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Written By

Cassandra Burns, Contributing Writer

Cassandra is a health writer who has been a contributor to Sleep Foundation since 2021. She writes about sleep products and reads emerging research to develop science-based articles that help demystify the connection between health and sleep. She's happy to report that she sleeps well most nights, which is probably thanks to her energetic dog and her other work managing a family-owned whitewater rafting business in Upstate New York.

Medically Reviewed by

Anis Rehman, MD, Internal Medicine Physician MD

Dr. Anis Rehman, MD is an American Board of Internal Medicine (ABIM) certified physician in Internal Medicine as well as Endocrinology, Diabetes, and Metabolism who practices in Illinois. He completed his residency at Cleveland Clinic Akron General, and fellowship training at the University of Cincinnati in Ohio. Dr. Rehman has several dozens of research publications in reputable journals and conferences.

Learn more about our Editorial Team

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