Dry mouth (xerostomia): approach
- Approach to a complaint
Dry mouth is most often caused by medicines. It leads to caries, thrush and trouble with speaking, swallowing and dentures.
What it is
Xerostomia is the feeling of a dry mouth; salivary hypofunction is a measurable reduction in saliva. The commonest cause is medication, especially drugs with anticholinergic effects (tricyclic antidepressants, antihistamines, antipsychotics, bladder antimuscarinics), diuretics and the burden of many drugs together. Other causes are dehydration, mouth breathing, diabetes, Sjögren disease, radiotherapy to the head and neck, HIV, hepatitis C, sarcoidosis and anxiety. Consequences include rapid caries at the gum line, candidiasis, burning, altered taste, difficulty chewing and swallowing, poor denture retention and halitosis.
Red flags
- Drugs are the leading cause; count anticholinergic load.
- Dry eyes plus dry mouth, joint pain or parotid swelling: Sjögren disease.
- After head and neck radiotherapy the damage is often permanent.
- Look for thirst, polyuria and weight loss (diabetes).
- A dry, sticky mucosa, frothy saliva and a mirror sticking to the cheek are signs.
Step-by-step approach
- Ask about drugs, fluid intake, mouth breathing, dry eyes, joint symptoms, radiotherapy and diabetes symptoms.
- Examine: dryness, caries at the gum line, candidiasis, parotid enlargement.
- Review and reduce drugs that dry the mouth, with the prescriber.
- Test as indicated: glucose or HbA1c, and for suspected Sjögren disease anti-Ro/SSA, anti-La/SSB, ANA and rheumatoid factor.
- Protect the teeth and treat symptoms while the cause is addressed.
Keys to the differential
- Dry mouth with unilateral parotid swelling that is hard or growing needs referral to exclude a tumour or lymphoma.
- People with Sjögren disease have a higher risk of lymphoma: watch for persistent gland swelling.
- Sugared sweets used to relieve dryness cause rampant caries.
Next step / Initial management
- Advise frequent sips of water, sugar-free gum or lozenges, saliva substitutes, humidified air, and avoiding alcohol mouthwashes, tobacco and caffeine.
- Daily high-fluoride toothpaste and dental review every three to six months.
- Residual gland function (Sjögren disease, after radiotherapy): a sialogogue such as pilocarpine or cevimeline may help, watching for cholinergic side effects.
- Suspected Sjögren disease: refer to rheumatology; persistent or hard gland swelling: refer to ENT or maxillofacial surgery.
Test yourself
Think of the answer, then tap the question to see it.
What is the most common cause of dry mouth?
Medications, especially those with anticholinergic effects.
Which antibodies support a diagnosis of Sjögren disease?
Anti-Ro (SSA) and anti-La (SSB), with ANA and rheumatoid factor often positive.
Why should people with dry mouth avoid sugared sweets for relief?
Because without saliva sugar causes rapid, extensive caries.
Connections
In Pharmacology3
Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.
Sources: Xerostomia (StatPearls Publishing (NCBI Bookshelf), 2023); Dry Mouth (National Institute of Dental and Craniofacial Research (NIDCR, NIH), 2024); Sjogren Disease (StatPearls Publishing (NCBI Bookshelf), 2025).
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Representative model, for educational purposes only.