Catathrenia: Why Do You Groan or Moan in Your Sleep?
If someone says you groan, moan, hum, or make a long strange sound while sleeping, catathrenia is one possible explanation. The most useful clue is not simply how the sound sounds. It is when the sound happens during breathing and whether snoring, gasping, choking, breathing pauses, or daytime sleepiness occur with it.
Catathrenia is sleep-related groaning or moaning that occurs mainly while breathing out. A classic episode often starts with an inhalation followed by a prolonged, noisy exhalation. It can repeat in clusters, and the sleeper may not know it is happening. Catathrenia is different from ordinary snoring, sleep talking, and the gasping or choking that can occur with sleep apnea. A recording may help describe the sound, but it cannot diagnose the condition by itself.
Does the Sound Fit Catathrenia?
You cannot diagnose catathrenia at home, but these observations can help you decide whether nocturnal groaning is a reasonable possibility to discuss with a healthcare professional.
This is one of the most useful clues. Classic catathrenia is an expiratory vocal sound rather than ordinary snoring on airflow through the throat.
Catathrenia often sounds more vocalized and prolonged than the rattling or rumbling sound usually described as snoring.
A classic sequence can include a deeper inspiration followed by a long noisy expiration. Not every recorded episode looks identical.
Published sleep studies describe repeated episodes during the night rather than only one ordinary sigh or isolated vocalization.
Those features do not prove sleep apnea, but they make it especially important not to assume every nighttime sound is harmless catathrenia.
What Does Catathrenia Sound Like?
Catathrenia is generally described as a groan, moan, hum, or unusual vocal sound during expiration. In classic episodes, a person takes a breath in and then produces a prolonged sound as air moves out.
Research has linked the sound to vocal-cord activity rather than the upper-airway tissue vibration that produces ordinary snoring. The exact sound varies, so a partner may describe it as groaning, humming, moaning, squeaking, or something difficult to name.
A deeper inhalation may begin the classic pattern.
The groan or moan occurs mainly during a prolonged breath out.
Similar episodes may occur in clusters during sleep.
Catathrenia vs Snoring, Sleep Talking, Apnea Sounds and Sighing
Many people search for catathrenia only after a partner says, “You make a strange moaning sound at night.” Comparing the sound with the breathing pattern can make that description much more useful.
| Sound or behavior | What it may sound like | Relationship to breathing | Useful distinction |
|---|---|---|---|
| Catathrenia | Groan, moan, hum, or sustained vocal-like sound. | Typically associated mainly with expiration. | A classic episode follows inhalation with a prolonged noisy breath out. |
| Snoring | Rattling, vibrating, rough, rumbling, or fluttering noise. | Produced by vibration of tissues as air moves through a narrowed upper airway. | It usually sounds more like airway vibration than a sustained vocalized groan. |
| Sleep talking | Words, phrases, mumbling, shouting, or speech-like sounds. | Not defined by a prolonged expiratory pattern. | The sound resembles speech rather than a recurring breathing-linked groan. |
| Apnea-related sounds | Snoring, quieter breathing or pauses, followed by snorting, choking, or gasping. | May occur around obstruction and repeated breathing interruptions. | Witnessed pauses, repeated gasping/choking, and marked daytime sleepiness deserve evaluation for sleep-disordered breathing. |
| Ordinary sigh | A deeper or more audible breath out. | Usually isolated rather than a repeating groaning pattern. | One occasional sigh is not the same as recurring nocturnal groaning. |
| Other vocalizations | Crying, laughing, shouting, unusual speech-like sounds, or noises associated with movement. | May not follow a stable expiratory pattern. | Movement, dream enactment, confusion, or other behaviors can change the differential. |
Groaning, Snoring, Gasping or Talking: Which Path Fits Best?
Catathrenia becomes a reasonable possibility to discuss, especially if the pattern repeats. Continue with this guide.
That pattern is more consistent with ordinary snoring. A snoring-focused guide is more useful than forcing the catathrenia label.
Prioritize evaluation for sleep-disordered breathing. If the main symptom is waking up choking, see Waking Up Choking at Night.
Speech-like vocalization is more consistent with sleep talking than a breathing-linked expiratory groan.
An isolated sigh is not the same as a recurring nocturnal groaning pattern.
Those features broaden the differential beyond catathrenia and are worth describing separately to a clinician.
What a Bed Partner May Notice
Catathrenia is often discovered by somebody else. The sleeper may remain unaware of the sound or hear about it only the next morning.
A partner may notice an inhalation followed by a long groan as the sleeper breathes out.
Episodes may repeat in clusters rather than appearing as one isolated sigh.
Some people continue sleeping through the sound and are surprised when someone describes it later.
Snoring, mouth breathing, choking, gasping, or pauses should be described separately rather than automatically labeled catathrenia.
What Causes Catathrenia?
Researchers do not yet have one proven explanation for every case of catathrenia. Studies support the idea that the sound involves the larynx and vocal cords during expiration, but why the breathing pattern develops is less clear.
Research has explored respiratory-control mechanisms, airway anatomy, glottic behavior, sleep-stage effects, and overlap with upper-airway obstruction. Newer reviews suggest that people grouped under the same catathrenia label may not all have identical breathing patterns.
Acoustic and sleep-study research supports vocal-cord vibration as an important part of the characteristic groaning sound.
Researchers have proposed differences in respiratory control as one possible contributor, but a single neurologic cause has not been established for all cases.
Some reported patients also show upper-airway narrowing or sleep-disordered breathing, but this does not mean obstruction explains every case.
Is Catathrenia a Parasomnia or a Breathing Disorder?
Older medical literature described catathrenia as a parasomnia. Later sleep-classification systems moved it into the sleep-related breathing-disorder category.
That classification history explains why older studies, newer reviews, and consumer-health websites do not always use exactly the same language.
Classification also should not be mistaken for a claim that catathrenia is the same condition as obstructive sleep apnea. It is not.
What to Observe Before a Sleep Appointment
You do not need to monitor every breath. A short, structured description can help a clinician decide whether the pattern sounds like catathrenia and whether further testing makes sense.
Note whether it is occasional, happens on several nights, or is reported almost every night.
Groan, moan, hum, snore, speech, gasp, choke, squeak, or another sound?
Does it happen mainly while breathing out, or does it seem unrelated to inhaling and exhaling?
Record witnessed pauses, repeated gasping, choking, snorting, or obvious breathing struggle separately.
Note unrefreshing sleep, morning headache, dry mouth, unusual fatigue, or excessive daytime sleepiness.
Bed-partner sleep disruption matters even when the sleeper feels well and can be a reasonable reason to discuss the problem.
Mention dream enactment, unusual movements, sleepwalking, repeated awakenings, or other behaviors rather than assuming they are part of catathrenia.
How Is Catathrenia Diagnosed?
A clinician may begin with the sleep history: what the sound is like, when it occurs, whether someone has witnessed breathing pauses, and whether there are daytime symptoms or other sleep problems.
When the diagnosis remains uncertain or another sleep disorder needs evaluation, an overnight polysomnogram can provide more context. Synchronized audio or video can help match the sound to airflow, breathing effort, oxygen levels, arousals, and sleep stage.
Approximate sound quality, timing, repetition, visible movement, and whether the noise seems tied to the breathing cycle.
Sleep stage, airflow measurement, respiratory effort, oxygen changes, arousals, or whether a clinically important sleep-breathing disorder is present.
Catathrenia and Groaning in Sleep FAQs
Why do I moan in my sleep?
Several nighttime behaviors can sound like moaning. Catathrenia is one possibility when a recurring groan or moan happens mainly during a prolonged breath out. Sleep talking, snoring, isolated sighs, apnea-related gasping, and other vocalizations can sound similar to a listener, so the breathing pattern and accompanying symptoms matter.
Why do I groan in my sleep but never hear myself?
People with catathrenia may remain asleep during the vocalization and learn about it from a partner, family member, roommate, or sleep study. Not remembering the sound does not confirm catathrenia, but lack of awareness is commonly reported.
Is catathrenia the same as snoring?
No. Catathrenia is mainly an expiratory vocalization, while ordinary snoring comes from vibration of upper-airway tissues as air moves through the airway. A person can have both.
Is catathrenia a type of sleep apnea?
No. Catathrenia and obstructive sleep apnea are different sleep-related breathing conditions. Some people may have catathrenia alongside upper-airway obstruction or sleep apnea, so repeated pauses, gasping, choking, or strong daytime sleepiness should be evaluated separately.
Is catathrenia dangerous?
Catathrenia may mainly create social or bed-partner disruption in some people, but a strange nighttime sound should not automatically be labeled harmless. Breathing pauses, choking, gasping, severe daytime sleepiness, or poor-quality sleep can point to another problem that deserves evaluation.
Can catathrenia happen during REM and non-REM sleep?
Yes. Older descriptions often emphasized REM sleep, but later studies and systematic reviews have documented catathrenia episodes during both REM and non-REM sleep.
Can anxiety or stress cause catathrenia?
Current evidence does not establish anxiety or stress as a single proven cause of catathrenia. The underlying mechanism remains uncertain, so it would be too strong to blame the condition on stress without evaluating the actual sleep and breathing pattern.
Does CPAP stop catathrenia?
CPAP has reduced groaning in some published patients, particularly in selected groups with sleep-disordered breathing, but it does not work universally and is not automatically required. A clinician should determine whether positive airway pressure is appropriate.
Can I diagnose catathrenia from an audio recording?
No. A recording may help a clinician hear the sound and see whether it seems linked to breathing, but it cannot measure important sleep-study signals such as airflow, breathing effort, oxygen, brain activity, arousals, or sleep stage.
Should my partner record me while I sleep?
A short recording may be useful when the sleeper knows about it and agrees. Avoid covert recording. Treat the file as private health-related information and share it only when there is a useful reason to do so.
Sources
- Martel Q, Maranci JB, Philippe C, Arnulf I. Sleep Medicine Reviews. 2024. Reviewed September 2026. Lamentations in the Night: A Systematic Review on Catathrenia . Used for current understanding of typical and atypical patterns, expiratory vocalization, sleep-stage findings and treatment uncertainty.
- Błaszczyk B, et al. Sleep and Breathing. 2024. Reviewed September 2026. The Clinical Characteristic of Catathrenia: A New Look at an Old Issue . Used for systematic-review evidence on REM/NREM distribution, clinical presentation and heterogeneity.
- Alonso J, Camacho M, Chhetri DK, et al. Journal of Clinical Sleep Medicine. Catathrenia (Nocturnal Groaning): A State-of-the-Art Review . Used for vocal-cord sound production, distinction from snoring and sleep talking, clinical evaluation and polysomnography context.
- Yu M, et al. Journal of Clinical Sleep Medicine. Mandibular Advancement Device as Treatment Trial for Catathrenia . Used for oral-appliance evidence in a selected treatment population and classification context.
- Abbasi AA, et al. Nocturnal Moaning and Groaning: Catathrenia or Nocturnal Vocalizations? . Used for polysomnography and synchronized audio/video differentiation of nocturnal groaning patterns.
- Cleveland Clinic. Last updated August 28, 2024; reviewed for this guide September 2026. Catathrenia (Nocturnal Groaning) . Used for current patient-oriented symptom, diagnosis and treatment context.
Describe the Breathing Pattern, Not Just the Noise
If somebody tells you that you moan or groan during sleep, do not start with “Do I have catathrenia?” Start with what actually happens.
Does the sound occur while you breathe out? Is it a long groan or ordinary snoring? Does it repeat? Are there pauses, choking, gasping, or obvious breathing struggle? Do you wake refreshed, or are you unusually sleepy during the day?
Those details help separate an unusual nighttime sound from a broader breathing or sleep problem and give a healthcare professional far more useful information than the phrase “I make noises in my sleep.”
