Most patients can recount when they have heard a spouse or bed partner make a noise in their sleep, but a more disturbing incident is hearing a bed partner groan during the night. When this happens to married couples, women often believe their husbands are having sexual dreams. But this condition actually has a medical name – catathrenia.

Catathrenia, or nocturnal groaning, is an uncommon parasomnia characterized by groaning that can last from 2 to 20 seconds. These sounds occur during exhalation, unlike snoring, which occurs during inhalation.

Patients with catathrenia are not awakened by the episodes, do not remember the incident and do not appear to experience any pain or mental anguish as a result. The patient may wake with a sore or dry throat, which will be the only evidence that something abnormal may be occurring during sleep.

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Catathrenia can begin at any age, but it usually starts in early adulthood, and affects more males than females. More than half of those with catathrenia have a family history of sleep disorders, including sleepwalking, sleep talking, night terrors and bruxism.

Catathrenia can occur intermittently throughout the night, but mainly happens during REM sleep. There is usually an increase in groaning during the later part of the night, as REM sleep periods are usually longer. The etiology of catathrenia is unclear.

Treatment with continuous positive airway pressure (CPAP) has been demonstrated effective, which leads some researchers to believe that catathrenia is a respiratory dysfunction. It is often confused with central apnea, since there is no respiratory effort or airflow, when the sound occurs. The phenomenon has socially negative effects as the sound can scare a bed partner and embarrass the patient. More studies need to be done to determine if this is in fact a breathing disorder or a parasomnia.

The only way to distinguish if the patient is experiencing catathrenia is to perform a polysomnogram. Remember, the disorder is rare, but if a spouse or family member complains of a loved one groaning during sleep, refer them to a sleep clinic for evaluation.

Sharon M. O’Brien, MPAS, PA-C, works at Presbyterian Sleep Health in Charlotte, N.C. Her main interest is helping patients understand the importance of sleep hygiene and the impact of sleep on health.


  1. British Snoring and Sleep Apnoea Association. “Catathrenia (Nocturnal Groaning).” Web. Accessed: 14 October 2012.
  2. American Sleep Association. “Catathrenia”. Web. Accessed: 14 October 2012.
  3. Vetrugno R, Lugaresi E, Ferini-Strambi L et al. “Catathrenia (Nocturnal Groaning): What Is It?” Sleep.2008;31(3):308-309.