Salivary gland hypofunction (objective evidence of diminished sa-
livary output) and xerostomia (the subjective sensation of dry mouth)
are common conditions. Patients with salivary gland hypofunction
and altered saliva composition are at increased risk for developing
caries, oral fungal infections, oral mucosal changes and debilitating
symptoms, swallowing problems, and diminished or altered taste.
The most prominent cause of xerostomia and salivary gland hy-
pofunction is the intake of medications interfering with the nervous
regulation of salivary secretion. Radiotherapy for cancer in the head
and neck region often leads to permanent and severe xerostomia and salivary gland hypofunction due to degeneration of the salivary gland
tissue involved in the radiation field. Sjögren’s syndrome, an autoim-
mune disease affecting exocrine glands, causes permanent xerosto-
mia and hyposalivation due to immune-mediated structural changes
in the salivary glands. Ageing may also be associated with structural
changes in the salivary glands that can influence the functions of sa-
liva. This article reviews the aetiopathogenesis, clinical manifesta-
tions, diagnosis, and management of conditions with salivary gland
hypofunction, common salivary gland diseases (mucous cysts and
sialoliths) and salivary gland tumours.