Cotton mouth, medically known as xerostomia, is oral dryness resulting from decreased saliva production. Saliva keeps the mouth lubricated, aids in digestion, and protects against pathogens. The sensation is often described as a sticky or dry feeling, sometimes accompanied by thicker saliva or bad breath.
Although not typically listed as a primary symptom of COVID-19, numerous studies identify dry mouth as a frequent oral manifestation. This symptom can appear early in the disease course, sometimes before recognized symptoms like fever or cough, and research suggests the SARS-CoV-2 virus may directly affect the salivary glands via ACE2 receptors.
Underlying Causes of Dry Mouth During Viral Illness
Dry mouth during a COVID-19 infection is often a non-specific consequence of being acutely ill, rather than a direct viral attack on salivary glands. The most common cause is dehydration, where insufficient fluid intake, fever, and sweating contribute to fluid imbalance and reduced saliva volume.
Mouth breathing is another contributor, especially when a person is congested due to a respiratory illness, causing oral tissues to dry out quickly during sleep. Furthermore, many over-the-counter medications used to treat viral symptoms, such as antihistamines and decongestants, list dry mouth as a side effect. These drugs interfere with natural saliva production, exacerbating xerostomia.
Other Reported Oral Manifestations of COVID-19
Dry mouth is one of several ways COVID-19 can affect the oral cavity. The most widely recognized oral symptom is dysgeusia, which involves an altered or complete loss of taste, and this is often reported alongside dry mouth. Studies suggest the virus’s ability to enter cells through ACE2 receptors in the taste buds or nervous system causes this taste alteration.
Studies have documented various oral mucosal lesions and inflammation, sometimes referred to as “COVID tongue.” These manifestations include ulcers, aphthous-like lesions, or a burning sensation on the tongue and other oral tissues. The tongue, lips, and palate are the most frequently affected areas, and these lesions are often painful. The presence of these other symptoms supports the idea that the SARS-CoV-2 infection has a direct impact on oral health.
Managing Dry Mouth Symptoms
Relieving dry mouth focuses on increasing moisture and stimulating saliva flow. Consistently sipping water is one of the most direct strategies, but it is important to take regular, frequent sips throughout the day rather than slow sipping. Sucking on sugar-free hard candies or chewing sugar-free gum helps stimulate the salivary glands to produce more natural saliva.
Using a cool-mist humidifier in the bedroom, particularly at night, can add moisture to the air and counteract the drying effect of mouth breathing. Over-the-counter saliva substitutes, such as sprays, gels, or lozenges, can provide temporary relief by coating the oral tissues. It is important to avoid alcohol-based mouthwashes, caffeinated drinks, and tobacco products, as these can all worsen the feeling of dryness. If dry mouth persists long after recovery, causes difficulty swallowing, or leads to new dental problems, consult a healthcare provider or dentist.