```html

Xerostomia (Dry Mouth)

What is Xerostomia?

Xerostomia, commonly called “dry mouth,” is the subjective feeling of insufficient saliva production in the mouth. Saliva is essential for lubricating oral tissues, beginning digestion, protecting teeth from decay, and maintaining taste and speech. When saliva flow drops below normal levels, patients may experience a dry, sticky feeling, difficulty swallowing, altered taste, and an increased risk of oral infections.

Although “xerostomia” describes the sensation, the underlying condition is hypo‑salivation—a measurable reduction in salivary gland output. The condition can be temporary (e.g., after a medication) or chronic (e.g., due to autoimmune disease).

Common Causes

More than 500 medications and many medical conditions can diminish saliva production. The most frequent causes include:

• Medications – antihistamines, antidepressants, antipsychotics, diuretics, antihypertensives, muscle relaxants, and certain pain relievers (source: Mayo Clinic).
• Radiotherapy to the head and neck – damage to salivary glands is a common side‑effect of cancer treatment.
• Autoimmune diseases – Sjögren’s syndrome, lupus, and rheumatoid arthritis can target salivary tissue.
• Diabetes mellitus – high blood glucose impairs glandular function and can cause chronic dryness.
• Neurological disorders – Parkinson’s disease, Alzheimer’s disease, and stroke may affect autonomic control of salivation.
• Dehydration – inadequate fluid intake, fever, vomiting, or excessive sweating.
• Substance use – tobacco, alcohol, and illicit drugs (especially methamphetamine) reduce saliva output.
• Obstructive sleep apnea (OSA) and mouth breathing – nocturnal mouth breathing leads to evaporative loss of moisture.
• Age‑related changes – although aging itself isn’t a direct cause, older adults often take multiple dry‑mouth‑inducing drugs.
• Genetic disorders – such as salivary gland agenesis or cystic fibrosis.

Associated Symptoms

Patients with xerostomia frequently report additional oral or systemic complaints:

• Sticky or cotton‑like sensation in the mouth.
• Difficulty speaking, chewing, or swallowing (dysphagia).
• Altered taste (dysgeusia) or a constant “bad taste.”
• Increased dental decay, cavities, and oral infections such as candidiasis.
• Cracked lips, dry or sore throat, and hoarseness.
• Gum inflammation (gingivitis) and rapid plaque buildup.
• Bad breath (halitosis) due to bacterial overgrowth.
• Feeling of “thick” saliva or mucus accumulation.

When to See a Doctor

Most cases of dry mouth are manageable with lifestyle changes, but you should schedule an appointment if you notice any of the following:

• Persistent dryness lasting longer than 2–3 weeks despite increasing water intake.
• Frequent mouth or throat infections, especially oral thrush.
• New or worsening tooth decay despite regular brushing and flossing.
• Difficulty swallowing foods or liquids, leading to choking or weight loss.
• Unexplained burning sensation on the tongue, lips, or inside the cheeks (burning mouth syndrome).
• Dry mouth that began after starting a new medication – you may need a dose adjustment.
• Associated systemic symptoms such as joint pain, dry eyes, or persistent fatigue, which could indicate an autoimmune disease.

Diagnosis

Evaluation typically proceeds in three steps: clinical assessment, objective testing, and investigation of underlying causes.

1. Medical History & Physical Exam

• Review of current medications, recent illnesses, radiation exposure, and lifestyle factors.
• Oral examination for signs of dryness, dental decay, plaque, oral candidiasis, and salivary gland swelling.

2. Objective Saliva Flow Tests

• Unstimulated whole‑saliva flow rate – the patient spits into a graduated container for 5 minutes. < 0.1 mL/min is considered low.
• Stimulated salivary flow – chewing paraffin wax or citric acid to stimulate glands; < 0.7 mL/min suggests dysfunction.
• Optional sialometry with scintigraphy (radioisotope imaging) for detailed gland function.

3. Laboratory & Imaging Tests (as indicated)

• Blood tests: complete metabolic panel, fasting glucose, antinuclear antibodies (ANA), anti‑SSA/Ro and anti‑SSB/La (Sjogren’s markers).
• Salivary gland imaging: ultrasound, MRI, or CT to look for obstruction, tumors, or radiation damage.
• Biopsy of a minor salivary gland (labial) if autoimmune disease is suspected.

Treatment Options

Therapy is directed at (1) relieving symptoms, (2) protecting oral health, and (3) addressing the root cause.

1. Address Underlying Causes

• Review and modify medications with your prescriber (e.g., switch to non‑anticholinergic antihistamines).
• Optimise diabetes control or treat autoimmune disease with disease‑modifying agents.
• If radiation therapy is the cause, consider salivary‑gland-sparing techniques or intensity‑modulated radiotherapy (IMRT).

2. Symptom‑relieving Measures

• Hydration – sip water frequently; aim for 2–3 L/day unless fluid‑restricted.
• Saliva substitutes – over‑the‑counter (OTC) mouth moisturizers (e.g., Biotène®, Mouth Kote®) containing glycerin, xylitol, or carboxymethylcellulose.
• Stimulating agents – sugar‑free chewing gum or lozenges with xylitol, sour candies, or pilocarpine (↑ parasympathetic stimulation) and cevimeline (muscarinic agonist) for patients without contraindications (prescribed by a physician).
• Prescription topical agents – fluocinonide oral gel for severe inflammation or antifungal rinses for candidiasis.

3. Oral‑Health Maintenance

• Brush with fluoride toothpaste twice daily and floss daily.
• Use alcohol‑free, fluoride‑containing mouth rinses.
• Schedule dental check‑ups every 6 months; ask dentist for fluoride trays or varnish.
• Avoid tobacco, excessive alcohol, and sugary or acidic foods that accelerate decay.

4. Adjunctive Therapies

• Acupuncture has shown modest benefit in xerostomia after radiotherapy (see NIH study).
• Low‑level laser therapy (LLLT) may stimulate residual gland tissue in select patients.

Prevention Tips

While some causes are unavoidable, many strategies can reduce the risk or lessen severity:

• Maintain adequate hydration throughout the day.
• Ask your healthcare provider about dry‑mouth side effects before starting new drugs.
• Use a humidifier at night, especially if you breathe through your mouth while sleeping.
• Chew sugar‑free gum after meals to naturally stimulate salivation.
• Limit caffeine and alcohol, both of which have diuretic effects.
• Practice good oral hygiene and visit the dentist regularly.
• For cancer patients, discuss saliva‑preserving radiation techniques with the oncology team.
• Manage chronic conditions (diabetes, hypertension) aggressively to prevent secondary gland damage.

Emergency Warning Signs

---

**References**

• Mayo Clinic. “Dry mouth (xerostomia).” https://www.mayoclinic.org
• Cleveland Clinic. “Xerostomia: Causes, Symptoms, and Treatment.” https://my.clevelandclinic.org
• National Institute of Dental and Craniofacial Research. “Dry Mouth (Xerostomia).” https://www.nidcr.nih.gov
• World Health Organization. “Oral health in the WHO global health agenda.” https://www.who.int
• National Center for Biotechnology Information. “Acupuncture for radiation‑induced xerostomia.” https://www.ncbi.nlm.nih.gov

```