How to Stop Catathrenia: Causes and Proven Treatments

Catathrenia, the medical term for nocturnal groaning, can be reduced or eliminated in many people with positive airway pressure therapy (CPAP) or oral appliances that reposition the jaw during sleep. The condition produces an unsettling, drawn-out moaning sound on each exhale, usually alarming bed partners far more than the person making the noise. Despite decades of case reports and small studies, there is no single cure that works for everyone, and the research base remains thin compared to better-known sleep disorders. What does exist, though, points toward a few approaches with genuine evidence behind them.

What Catathrenia Actually Sounds Like

If you have never heard catathrenia, imagine a long, low groan or moan that lasts anywhere from about one second to over a minute, repeating in clusters throughout the night. The sound is produced during exhalation, which distinguishes it immediately from snoring, which happens on the inhale. One study documenting over 3,700 groaning episodes across 23 patients found the average groan lasted about 11 seconds, though some stretched beyond a minute.¹ The groans tend to be rhythmic or semi-rhythmic, and acoustic analysis confirms they are produced by the vocal cords, giving them a tonal quality with clear harmonics, quite different from the irregular, turbulent noise of typical snoring.²

Bed partners often describe it as eerie, distressing, or even sexual-sounding, which adds an awkward social dimension that can be just as burdensome as the sleep disruption itself. The person groaning is almost always unaware of the sound and typically does not wake up during episodes. Most of the clinical concern, in fact, comes from the bed partner or family members rather than the groaner.

Why It Happens

The honest answer is that no one fully understands the cause. Catathrenia sits in an awkward classification limbo, which reflects genuine scientific uncertainty about its mechanism. It was originally classified as a parasomnia (a category that includes sleepwalking and sleep terrors), but the most recent International Classification of Sleep Disorders moved it into the respiratory disorders category.³ That shift happened because the groaning is tied to a distinctive breathing pattern: a deep breath in, followed by an abnormally prolonged exhale during which the vocal cords partially close and vibrate, producing the sound.⁴

Researchers studying the upper airway anatomy of people with catathrenia have found some structural differences compared to both healthy sleepers and people with obstructive sleep apnea. These include a narrower space behind the soft palate, a lower resting position of the hyoid bone (the small bone at the base of the tongue), and a shorter, thinner tongue.⁵ These features suggest that something about the airway’s shape predisposes certain people to partial expiratory obstruction during sleep, but the details remain fuzzy. Pressure measurements taken during groaning episodes show mildly positive swings at the start of expiration, consistent with partial upper airway obstruction on the way out rather than the way in.⁴

A 2024 systematic review noted that some patients present with a more “atypical” form of catathrenia: shorter, more regular moans occurring during lighter stages of non-REM sleep, often alongside mild upper airway obstruction.⁶ The “classic” form, by contrast, clusters heavily in REM sleep. In the acoustic analysis study mentioned earlier, about 70% of patients had REM-predominant groaning.¹ Why REM sleep triggers the behavior so reliably in most patients is still unknown, though the general muscle relaxation of REM sleep may make the airway more collapsible on exhale.

Who Gets Catathrenia

Catathrenia appears to affect men and women at roughly equal rates, according to a systematic review of the existing literature.⁷ That is unusual for a sleep-related breathing issue; obstructive sleep apnea, for comparison, is far more common in men. The condition can start at any age, including infancy. In one pediatric study, the average age of onset was about six years old, though there was often a delay of a couple of years before the condition was formally identified.⁸ Only about a quarter of the children in that study were referred specifically for groaning; most were actually referred for breathing concerns during sleep, and the catathrenia was picked up incidentally.

Exact prevalence numbers are hard to come by because most studies are small case series or single-center retrospective reviews. Many people with catathrenia never seek medical attention because they sleep through it and have no idea it is happening. The condition comes to clinical attention almost exclusively because someone else in the household hears it and raises the alarm.

Getting the Diagnosis Right

A sleep study, specifically a polysomnogram with synchronized audio and video recording, is the standard way to confirm catathrenia. The audio component is critical. Without it, groaning episodes can be confused with central apneas on the respiratory tracings, because both involve pauses in normal breathing rhythm. The characteristic pattern on a sleep study is a deep inspiration followed by a long, slow expiration with audible groaning, clearly different from the repeated obstructive collapse seen in sleep apnea or the abrupt respiratory halt of a central apnea.⁹

One case report emphasized that even in a six-year-old child, audio-video documentation during the sleep study was essential for nailing the diagnosis.¹⁰ If your sleep lab only runs standard polysomnography without audio or video channels, the groaning may be noted in the technician’s comments but could be mislabeled or missed entirely. If you suspect catathrenia, it is worth asking whether the facility uses audio-video recording before scheduling the study.

Conditions That Mimic Catathrenia

Getting the right diagnosis matters because a few conditions can look or sound similar but require completely different treatment. The differential includes sleep talking, stridor, laryngospasm, snoring, and nocturnal seizures.¹¹

The most consequential mimic is nocturnal frontal lobe epilepsy, which can produce vocalizations during sleep that sound remarkably like catathrenia. Case reports have documented patients initially diagnosed with catathrenia who turned out to have seizures originating in the frontal operculum.¹² The treatment paths diverge sharply: catathrenia responds to airway pressure, while seizures require anticonvulsant medication. If your groaning episodes are accompanied by unusual movements, post-episode confusion, or do not respond to CPAP, epilepsy-related vocalization should be on the table.

Snoring is the most common false match and the easiest to rule out. Snoring is an inspiratory sound with an irregular, turbulent acoustic signature, while catathrenia produces a tonal, harmonic expiratory sound. Acoustic analysis shows that the two have distinct waveform characteristics: snoring signals are irregular and lack the clear harmonics seen in groaning.² A bed partner who pays attention to whether the noise occurs when you are breathing in or breathing out can often tell the difference before a sleep study does.

CPAP and Positive Airway Pressure

The treatment with the most reported success is continuous positive airway pressure, the same CPAP therapy used for obstructive sleep apnea. A pressurized stream of air delivered through a mask appears to splint the upper airway open during exhalation, preventing the partial closure that produces the groaning sound. Multiple case series and reports describe significant reduction or complete elimination of groaning with CPAP use.

In a pediatric case series, three children treated with CPAP showed improvement in both the groaning itself and related daytime symptoms like fatigue. The authors recommended CPAP when catathrenia leads to sleep disruption or negative daytime effects.¹³ Earlier work similarly described CPAP response, though the original classification debate noted that CPAP’s effectiveness in catathrenia was still uncertain at that time.¹⁴

The catch is that CPAP is not a trivial therapy to live with. Wearing a mask every night takes adjustment, and adherence rates for CPAP are famously poor even in sleep apnea, where the health stakes are higher. For someone with catathrenia who sleeps perfectly well and is not personally bothered by the noise, the burden-to-benefit ratio of nightly CPAP can feel steep. The person most motivated to pursue treatment is often the bed partner, not the patient, which can make sticking with CPAP harder.

Oral Appliances

For people who cannot tolerate CPAP or prefer a less cumbersome option, mandibular advancement devices offer an alternative. These are custom-fitted dental appliances that push the lower jaw slightly forward during sleep, widening the space behind the tongue and in the throat. A study testing these devices in catathrenia patients found that groaning episodes dropped significantly, roughly cutting the groaning rate in half on average.¹⁵

The same study found that the degree of vertical opening and changes in the cross-sectional area of the lower throat were positively related to how well the device worked. In other words, the more the device physically opened up the airway, the better the result. Age had a negative effect on efficacy, meaning younger patients tended to respond better.¹⁵ These appliances need to be fitted by a dentist trained in sleep medicine, and they can cause jaw discomfort or changes in bite alignment over time, so they are not entirely hassle-free either. Still, for many people, a dental appliance is easier to tolerate night after night than a CPAP mask.

What About Medication or Behavioral Approaches

If you search online for catathrenia treatments, you will run into anecdotal suggestions: sleeping on your side, avoiding alcohol before bed, managing stress, trying various supplements. None of these have been studied in controlled trials for catathrenia specifically. Positional therapy (avoiding the supine position) is sometimes mentioned because some patients groan more while sleeping on their backs, but the evidence is limited to incidental observations in case reports rather than formal testing.

No medication has been reliably shown to treat catathrenia. Unlike some parasomnias that respond to clonazepam or other benzodiazepines, catathrenia does not have a pharmacological go-to. Isolated case reports have tried various drugs with inconsistent results, but nothing has risen to the level of a recommended therapy. This is partly a consequence of the condition being rare enough that no one has been able to run a meaningful drug trial.

The practical upshot is that if you want evidence-based treatment, your realistic options are CPAP and oral appliances. Everything else falls into the “might help, might not, nobody has tested it properly” category. For many people, especially those whose catathrenia is mild and whose bed partner can use earplugs or sleep in a separate room on bad nights, watchful waiting is the most reasonable approach. The condition does not cause oxygen desaturation or pose known cardiovascular risks the way obstructive sleep apnea does, so the main harm is social and relational rather than medical.

Catathrenia in Children

Parents who discover their child groaning loudly during sleep are understandably alarmed, but catathrenia in children follows a similar pattern to the adult version. In a pediatric cohort, most children were originally referred for breathing concerns during sleep, and the catathrenia was found incidentally during the sleep study.⁸ The average onset was around age six, though some parents reported noticing it from birth.

Treatment decisions in children involve the same options but with more caution. CPAP has been used successfully in pediatric cases when the groaning disrupts the child’s sleep or causes daytime problems.¹³ Oral appliances are trickier in children because the jaw is still growing, and any device that repositions it could theoretically affect dental development. Whether children “outgrow” catathrenia is an open question without a clear answer in the literature. Some parents report improvement over time; others see it persist into adolescence and adulthood.

When Your Bed Partner Has Catathrenia

Much of the real-world burden of catathrenia falls on the person who has to listen to it. If you are the bed partner, a few practical strategies can help while the groaner pursues (or decides against) formal treatment. White noise machines or fans can partially mask the sound. Earplugs rated for higher noise reduction can make a meaningful difference, though the tonal, harmonic quality of catathrenia tends to cut through ambient noise more effectively than snoring does. Sleeping in a separate room on particularly bad nights is a perfectly reasonable option and not a sign of relationship failure; sleep medicine specialists commonly recommend it for couples dealing with disruptive sleep disorders.

Recording the sounds on your phone can also be genuinely useful. Many people with catathrenia have never heard themselves groan and may not take the complaint seriously until they hear a recording. The recording is also helpful for the sleep physician, who can often make a preliminary assessment of whether the sound pattern is consistent with catathrenia before ordering a formal sleep study. Some smartphone apps designed for tracking snoring can capture overnight audio, though they are not a substitute for a proper polysomnogram with synchronized physiological data.

If you and your partner are considering CPAP or an oral appliance, it is worth framing the conversation around shared sleep quality rather than making the groaner feel defective. People are more likely to stick with a nightly treatment when they see it as something they are doing for the relationship rather than something being imposed on them because of an embarrassing noise they cannot even hear.

The Classification Debate and Why It Affects You

Whether catathrenia is a respiratory disorder or a parasomnia might sound like an academic turf war, but it has practical consequences for patients. Its current classification as a sleep-related breathing disorder means that CPAP and oral appliances are more likely to be covered by insurance, since those are standard respiratory treatments. If it were still classified as a parasomnia, the recommended treatments might lean more toward medications or behavioral interventions, and getting CPAP approved could be harder.

The reclassification also shapes how sleep physicians think about the condition when they encounter it. A doctor who views catathrenia through a respiratory lens will focus on airway mechanics and may be quicker to trial CPAP. One who still thinks of it as a parasomnia might be more inclined to try clonazepam or suggest that no treatment is necessary. If you feel your doctor is dismissing the condition or not considering airway-based treatments, pointing to the current classification can be a useful conversation starter. The evidence increasingly supports the idea that something about the airway, not something about dream content or arousal mechanisms, is driving the sound. Treatment choices should follow that understanding.