An Overview of Catathrenia (Sleep Groaning)

In the still of the night, a prolonged and disruptive groan comes from the person lying next to you. Or, perhaps, you wake in the morning and are told that you are the one who spent the night moaning and groaning in your sleep. In catathrenia, one of the sleep behaviors collectively called parasomnias, this frequently occurs. What is catathrenia, how is it diagnosed, and are there effective treatments available?

Catathrenia means a person makes a strange sound when breathing out during sleep -- sounding similar to groaning or moaning. These sounds occur with an exhalation, but they are also associated with other changes in the breathing pattern.

There may be a slowing of the timing of breaths, called bradypnea. In addition, an affected person may even hold his or her breath briefly prior to the initiation of the groaning. There are otherwise no clear signs of respiratory distress observed.

When witnessed, catathrenia may most commonly sound like prolonged moans or groans. It may also sound like humming and may even seem mournful. The noises can be very loud.

Many times, catathrenia comes to medical attention when it is so loud that it becomes disruptive to others. This may occur in dormitories at college or in the military, or when consistently sharing a bed with another person for the first time.

These groaning sounds may occur intermittently in clusters with each lasting for five to 50 seconds. There may be multiple groans recurring for a few minutes up to one hour. These events usually arise during rapid eye movement (REM) sleep but may even occur in stage 2 of non-REM sleep.

Catathrenia often begins in childhood. It more often affects young men and may persist for years. The cause is not entirely known, but it is not due to any underlying psychological or psychiatric distress.

Catathrenia is often not remembered by the person who experiences it. Aside from some hoarseness upon awakening, there may be few associated symptoms that can be self-observed. Without a witness, the sleep groaning may go unnoticed.

A formal diagnosis of catathrenia can be confirmed with a diagnostic sleep study called a polysomnogram. This study is performed in a sleep center and will show alterations in the respiratory pattern and may even document the groaning sounds.

It is also important to distinguish catathrenia from other breathing disturbances and sleep disorders. There is some research that suggests a relationship between catathrenia and sleep apnea, in which the airway partially or completely collapses during sleep and disrupts breathing. It is theoretically possible that catathrenia may be a way to protect the airway during sleep, much like teeth grinding.

Before accepting catathrenia as a diagnosis, other conditions should be ruled out, including:

• Snoring
• Somniloquy (sleep talking)
• Stridor
• Asthma

Though the afflicted individual typically is unaware of the groaning sounds, it may cause significant sleep disturbance to the bed partner or others nearby. 

The success of treatments for catathrenia has varied. As it is somewhat poorly understood why it occurs, the treatments may not always be effectively targeting the underlying cause.

Due to the possible relationship with sleep apnea, continuous positive airway pressure (CPAP) has been tried with some success. Not everyone with catathrenia responds to this treatment, however.

Occasionally the use of medications that can disrupt REM sleep may be used if the bed partner finds the groaning particularly bothersome. If it predominately occurs during this stage of sleep, it may improve with this intervention.

If you or your bed partner are experiencing catathrenia, start by speaking with a sleep specialist. After appropriate testing, you can pursue a treatment that returns quietly to your sleep.