Some causes of dry mouth during sleep are mouth breathing, different medical conditions and the side effects of certain medicines. Mouth breathing is a main cause of dry mouth at night time, states MedicineNet. Mouth breathing can occur if a person snores, has sleep apnea, wears dental retainers, or has obstructed nasal passages, notes the OraCoat website.
Dry mouth, also referred to as xerostomia, develops when salivary glands do not make sufficient amounts of saliva in the mouth. Besides mouth breathing, another cause for dry mouth can be the use of different medications, such as drugs for hypertension, antihistamines, diuretics and antidepressants, notes MedicineNet. Dehydration can also lead to dry mouth at night.
Xerostomia can also be the symptom of many different medical conditions, including diabetes, sarcoidosis, Addison's disease, rheumatoid arthritis and bulimia. Dry mouth also is a characteristic symptom of the autoimmune disease called Sjogren's syndrome, states the Sjogren's Syndrome Foundation.
Some simple solutions to alleviate night time dry mouth are to use a humidifier in the bedroom, stay hydrated by drinking plenty of water during the day and avoiding caffeinated drinks. Medications, which increase saliva production, may also be necessary for some patients. However, because many medical conditions can cause dry mouth, patients may also need medications to treat any of these underlying conditions. Additionally, if a person experiences the symptom of dry mouth, it is advisable to see a doctor for a proper diagnosis.