Xerostomia (ICD-10 R68.2: Dry mouth, unspecified) refers to the symptom of dry mouth. Furthermore, xerostomia and hyposalivation (secretion of insufficient amounts of saliva) or oligosialia Oligosialia (< 3.5 ml saliva/ in 5 minutes) is usually defined as subjectively perceived oral mucosal dryness combined with a severe reduction in resting salivary flow (total resting salivary flow rate: < 0.1 ml/min; stimulated total salivary flow rate: < 0.5 ml/min).
Normally, the salivary glands produce between 500 and 1,500 ml of saliva daily. Significantly less saliva is produced at rest (resting saliva) than when stimulated by a stimulus (stimulated saliva). Saliva protects and cleans the oral cavity.
Dry mouth can occur physiologically in stressful situations, with mouth breathing or as a symptom of aging. However, it can also be a symptom of a disease or a side effect of medication (common) or therapy.
Frequency peak: The symptom occurs predominantly in older age, because older people often have to take medication, which can lead to dry mouth. Furthermore, they drink less due to the decreasing feeling of thirst and saliva production decreases due to age.
Xerostomia can be a symptom of many diseases (as discussed under “Differential Diagnoses”).
Course and prognosis: In the majority of cases, dry mouth is short-lived and disappears with simple measures such as drinking plenty of fluids. If additional symptoms occur, such as pain when chewing, swallowing, or speaking, a physician should be consulted.
