Dry mouth — when reduced saliva starts affecting daily life.
Saliva does more than people realise — it lubricates speech and swallowing, protects teeth from decay, neutralises acid, controls bacteria, and carries taste. When saliva production drops, the consequences ripple through the whole mouth. Specialist investigation can identify the cause and the management can make a real difference to quality of life.
What it is
Reduced saliva — the clinical term is xerostomia.
Dry mouth describes a sensation, but xerostomia describes the underlying condition — a measurable reduction in salivary flow. The two often go together, but not always: some patients feel dry despite normal flow, and some have very low flow without much subjective complaint.
Either way, the consequences are real: increased risk of dental decay, oral infections, difficulty eating dry food, altered taste, mouth sores, denture intolerance, bad breath, and disrupted sleep.
Common causes
Medication is by far the most common cause.
Most adult dry mouth is drug-induced. Over 400 medications list dry mouth as a side effect — antihypertensives, antidepressants, antihistamines, diuretics, opioids, and many others. The more medications a person takes, the higher the cumulative effect.
Other significant causes include:
- Sjögren's syndrome and other autoimmune conditions
- Radiation therapy to the head and neck
- Dehydration and chronic mouth breathing
- Anxiety and chronic stress
- Diabetes (particularly when blood sugar is poorly controlled)
- Salivary gland disorders, including stones and infections
How we investigate it
Identifying the cause is the first treatment step.
A specialist consultation includes a thorough medical history (with attention to every medication, current and recent), an oral examination assessing salivary flow and its effects, and — where indicated — salivary flow measurement, blood tests for autoimmune markers, or imaging of the salivary glands.
If Sjögren's syndrome is suspected, we work with your physician and may recommend referral to a rheumatologist. If a medication is the culprit, we discuss alternatives with your prescribing doctor — sometimes a small change makes a substantial difference.
Management
Symptom relief, dental protection, and addressing the cause.
Treatment usually combines three approaches:
Address the cause where possible. Medication review, hydration habits, treatment of underlying conditions.
Stimulate saliva production. Sugar-free chewing gum, sialogogues (medications that stimulate salivary flow where flow is recoverable), specific oral rinses.
Protect against the consequences. High-fluoride toothpaste, saliva substitutes, careful dental maintenance, and treatment of any decay that has developed. Dry-mouth patients need a more attentive maintenance schedule than the average patient.
Common questions
Frequently asked.
Clinical content
Reviewed by Dr Christa Blignaut and Dr Leande Kotze. Last reviewed 16 May 2026.