Dry mouth (xerostomia)
A persistent feeling of dryness in the mouth from reduced saliva. By far the commonest cause is medication, but it can also reflect dehydration, poorly controlled diabetes, or the autoimmune condition Sjögren's — and beyond discomfort, it raises the risk of tooth decay.
What it means
Dry mouth is the sensation of insufficient saliva, leaving the mouth dry, sticky and sometimes sore, with a dry tongue, cracked lips, bad breath, difficulty chewing, swallowing or speaking, and altered taste. Saliva does more than moisten — it protects the teeth and controls mouth bacteria — so persistent dry mouth also raises the risk of tooth decay, gum disease and mouth infections. The single commonest cause is medication: hundreds of drugs reduce saliva, including many antidepressants, antihistamines, blood-pressure and bladder medicines, and painkillers, and the effect adds up when several are taken. Other causes include dehydration, mouth-breathing (especially with a blocked nose or snoring), anxiety, poorly controlled diabetes, radiotherapy to the head and neck, and — importantly — Sjögren's syndrome, an autoimmune condition that dries up saliva and tears, so a dry mouth combined with dry eyes is a specific clue worth acting on.
Common causes
- Medications — by far the commonest cause; antidepressants, antihistamines, blood-pressure and bladder drugs, painkillers, and many more, especially in combination.
- Dehydration — not drinking enough, or fluid loss.
- Mouth-breathing — blocked nose, snoring, especially at night.
- Anxiety and stress.
- Poorly controlled diabetes — with thirst and frequent urination.
- Sjögren's syndrome — autoimmune; dry mouth plus dry eyes is a key clue.
- Radiotherapy to the head and neck.
- Ageing — often really a medication effect rather than age itself.
Lab work-up approach
Dry mouth is usually diagnosed from the history — especially a medication review, which is the highest-yield step. Blood tests are targeted: fasting glucose or HbA1c if diabetes is possible (particularly with thirst and frequent urination), and, when dry mouth is combined with dry eyes or other autoimmune features, tests for Sjögren's syndrome (ANA, anti-Ro/SSA and anti-La/SSB antibodies, inflammatory markers). Mediora.AI can surface a glucose or autoimmune pattern from your results when the picture fits, but for most dry mouth the key steps are reviewing medications and looking after the teeth, with your doctor and dentist.
Tests Mediora.AI can interpret
Related conditions
Panels to consider
When to see a doctor
For occasional or mild dry mouth, simple measures help — sipping water, sugar-free gum or lozenges to stimulate saliva, avoiding caffeine, alcohol and smoking, and treating a blocked nose. Importantly, review your medications with your doctor or pharmacist, as these are the commonest cause and sometimes can be adjusted (never stop them yourself). See a doctor if dry mouth is persistent, especially with dry eyes, joint pain or fatigue (which may indicate Sjögren's), or with thirst and frequent urination (which may indicate diabetes). Because dry mouth raises the risk of tooth decay, regular dental care is important. Mediora.AI helps screen the diabetes and autoimmune contributors; persistent dry mouth is assessed with your doctor.