Many people who rarely experience unusual sleep sounds suddenly find themselves groaning loudly during sleep when they catch an acute respiratory illness. This nocturnal sound is often a temporary, sickness-induced version of catathrenia, or sleep groaning. While catathrenia is a distinct, chronic sleep disorder, the physiological changes brought on by a cold, the flu, or severe allergies can dramatically worsen its characteristic sound. This temporary increase in nighttime vocalization stems from the body’s struggle to move air through inflamed and congested upper airways during sleep.
Defining Catathrenia and Its Characteristics
Catathrenia is classified as a sleep-related breathing disorder that manifests as a prolonged, involuntary, and often high-pitched moan or groan during sleep. The sound is produced exclusively during exhalation, which is a primary feature distinguishing it from common snoring. Snoring is caused by the vibration of soft tissues in the pharynx and occurs as a person inhales.
The groaning sound originates from the larynx, or voice box, and is thought to be caused by the sleeper attempting to prolong their breath against a partially closed glottis. This results in a drawn-out, monotone sound that can last for several seconds, often ending with a sigh or a snort. The sleeper is typically unaware of the noise, which is usually brought to their attention by a bed partner. Episodes often occur in clusters and are most commonly observed during the Rapid Eye Movement (REM) stage of sleep.
Respiratory Mechanics and Groaning During Illness
Acute respiratory infections, such as a cold or flu, introduce significant inflammation and swelling into the upper airway structure. This infection-related edema causes the nasal passages and the soft tissues of the throat to narrow, increasing the resistance against airflow. The body must then work harder to push air out, especially since groaning involves a prolonged and forceful exhalation against an already restricted opening.
As the body fights the congestion, the passive process of normal breathing shifts toward an active, forced expiration. This increased respiratory effort, often recruiting abdominal muscles, is necessary to overcome the heightened resistance in the inflamed airway. This forceful expulsion of air through the narrowed, swollen throat dramatically increases the vibration of the vocal cords, making the groaning sound louder and more frequent.
Increased mucus production, particularly post-nasal drip, also plays a significant role. This excess mucus can irritate the delicate tissue of the larynx and pharynx, the structures responsible for producing the sound. The irritation and resulting inflammation can cause involuntary muscle spasms or altered tension in the vocal cords, contributing to the prolonged, noisy exhalation. Fragmented sleep that often accompanies illness can lead to more time spent in the sleep stages associated with groaning, amplifying the problem.
Diagnosis and When to Seek Medical Guidance
For a groaning sound to be formally diagnosed as chronic catathrenia, a physician will typically order an overnight sleep study, known as polysomnography. This test monitors brain activity, breathing patterns, heart rate, and body movements, often including an audio recording to capture the characteristic expiratory groan. The sleep study is also used to differentiate catathrenia from other sleep-related breathing disorders, such as obstructive sleep apnea (OSA).
If nocturnal groaning only appears during a brief period of sickness and resolves once the illness clears, it is likely a temporary symptom of congestion and inflammation. However, medical guidance should be sought if the groaning persists long after the acute symptoms have passed. Other red flags that warrant immediate medical evaluation include:
- Observed pauses in breathing.
- Gasping or choking sounds.
- Excessive fatigue.
- Morning headaches or difficulty concentrating.
These symptoms can indicate a more serious underlying condition, such as OSA, which requires specific treatment.
Strategies for Symptom Relief and Management
When groaning is exacerbated by a temporary illness, management focuses on reducing upper airway congestion and inflammation. Using a cool-mist humidifier in the bedroom can help soothe irritated airways and loosen thick mucus, making breathing easier. Nasal saline rinses or sprays can mechanically clear the nasal passages, reducing the post-nasal drip that irritates the larynx.
Over-the-counter nasal decongestants may be used temporarily to reduce swelling in the nasal lining, but they should only be used for a few days to avoid a rebound effect. Positional therapy also offers relief, as elevating the head of the bed by a few inches can help drain congestion and reduce the likelihood of airway collapse. Maintaining good sleep hygiene, such as a consistent sleep schedule, supports stable sleep architecture and helps mitigate sleep-related breathing disturbances.