Home » Sleep Disorders » Groaning
December 2020 |  Reviewed by:  Rafael J. Sepulveda, MD

What is groaning?

Sleep-related groaning, also called catathrenia, causes you to groan vocally while you sleep. Sleep-related groaning is a long-lasting disorder that often occurs nightly.

The groaning sound is usually quite loud. Your breathing becomes unusually slow during a groaning episode. You take in a slow, deep breath. Then you make a long moaning, humming or cracking sound while breathing out. The sound can last from only a few moments to more than 40 seconds. It always ends with a sigh or a grunt. Groans often repeat in clusters for two minutes to one hour. These clusters of groaning may recur many times per night.

Facial expressions are calm and do not reflect anguish. Despite the moaning sound, the groans do not seem to be related to any emotions. Groaning can occur when lying in any position. But it tends to stop when you change positions in bed. Then it may resume later in the night.

If you are groaning, you may be unaware of the sounds. The groans are much more disturbing to bed partners, roommates or family members who can hear them.

Other descriptions of the groaning sound include the following:

  • High-pitched or cracking sounds
  • Loud humming
  • Loud roaring

The cause of sleep-related groaning is not known. It is not related to any problem with breathing. There is also no abnormal brain activity involved. A physical exam tends to show no related medical cause. There also does not appear to be any link to mental disorders.

You may have a mild case of restless sleep or daytime fatigue as result of sleep-related groaning. Otherwise, there is usually no major sleep complaint. You may also have a hoarse voice or sore throat in the morning.

The groaning appears more often during REM sleep. There are four stages of sleep that make up one sleep cycle. You normally complete four to six sleep cycles in one night. The fourth stage of each cycle is called REM sleep. It usually begins 90 to 120 minutes after you fall asleep. REM sleep makes up about 20 to 25 percent of your total sleep time and it varies with age.

The first REM period tends to last for only a few minutes. The REM stage gets longer during each sleep cycle. Your last period of REM sleep may last as long as an hour. These latter periods of REM sleep include most episodes of groaning. Groaning may occur from time to time during other stages of sleep.

A moaning sound can also occur during an epileptic seizure. This sound would not occur on a regular basis like groaning does. A moaning type of sound can also be made by snoring. But the primary sound of snoring occurs when you inhale. Groaning occurs when you exhale. Some people can make a harsh, shrill, creaking sound when they breathe. This is called stridor. It may occur mainly when they sleep. But stridor happens with almost every breath. Unlike groaning, it does not appear in blocks of time in the night.