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Persistent dry mouth can affect how your food tastes and may even affect the health of your teeth.

Lack of saliva is a common problem that may seem little more than a nuisance. But don’t ignore it. Persistent dry mouth can affect how your food tastes and may even affect the health of your teeth. Although the treatment depends on the cause, dry mouth is often a side effect of medication.

The saliva in your mouth serves many purposes. Most noticeably, saliva makes it easier to talk. Saliva also helps to prevent tooth decay. It washes away food and plaque from your teeth. Minerals found in saliva help repair early tooth decay. Saliva also limits bacterial growth that can dissolve tooth enamel or lead to mouth infections; and saliva neutralises damaging acids in your mouth. Saliva enhances your ability to taste your food and makes it easier to swallow. In addition, enzymes in saliva aid in digestion. On any given day, a healthy adult produces about 3 pints of saliva. Still saliva goes unnoticed unless you do not produce enough. In that case, the result is xerostomia (zerostom-ee-ah) – the medical term for dry mouth.

Signs and symptoms

Aside from the sensation of dryness in your mouth, xerostomia may result in

  • Saliva that seems thick, stringy
  • Sores or split skin at the corners of the mouth
  • Bad breath
  • Difficulty speaking, swallowing
  • A burning or tingling sensation of your tongue
  • An altered sense of taste
  • Increased plaque, tooth decay and gum disease


Dry mouth was once thought to be part of aging but most xerostomia is actually related to the medications taken by older adults rather than to their age. Many common medications, including some over-the-counter drugs, produce dry mouth as a side effect.

Among the more likely drugs to cause problems are some of the drugs used to treat depression and anxiety, antihistamines, high blood pressure medications, anti-diarrhoea medications, muscle relaxants, drugs for urinary incontinence and Parkinson’s disease medications.

There can also be other causes, among them cancer therapy. Chemotherapy drugs can change the nature of saliva and the amount produced.

Radiation treatments to your head and neck can cause damage to your salivary glands.

Nerve damage to your neck and neck area from an injury or surgery can also result in xerostomia. Other conditions that can lead to dry mouth include the autoimmune disease Sjogren’s syndrome, endocrine disorders, Alzheimer’s disease, stroke, anxiety disorders and depression.

  • In addition, smoking or chewing tobacco can effect saliva production, aggravating dry mouth.
  • Snoring and breathing with your mouth open can also contribute to the problem.


To determine if you have dry mouth, your doctor or your dentist will likely examine your mouth  and review your medical history. Sometimes you may need blood tests and imaging scans of your salivary glands for your doctor to determine the cause. If your doctor believes medication to be the cause, he/she may adjust the dosage or switch you to another medication that does not cause dry mouth.

Using a fluoride rinse or brush-on fluoride gel before bedtime may also offer protection.

You can also try

  • sip water regularly, To avoid dehydration drinking two litres of fluid a day is recommended
  • breathe through your nose, not your mouth
  • add moisture to air at night with a room vaporiser
  • snoring and breathing with your mouth open can also contribute to the problem.
  • seek dietary advice. Some foods make dryness worse. Referral to a dietician is usually through your doctor
  • apply lip balm to keep lips moist
  • visit your dentist. They can remove some irritants that may be making the problem worse.
  • remove any dentures at night. Give your mouth a chance to recover
  • ask your dentist or doctor about the possibility of using artificial saliva
  • avoid alcohol and do not smoke – both make dryness worse
  • do not use mouthwashes that are not prescribed by your dentist or doctor. Many contain alcohol


The PAI would like to thank Sean O’Sullivan, Consultant Neurologist for reviewing and endorsing this leaflet.

Other Relevant Information Pages

  1. Dental Health in Parkinson’s Disease
  2. Speech and Language Problems in Parkinson’s disease

DISCLAIMER – The information on these pages is not intended to be taken as advice. No changes to your treatment should be made without prior consultation with your doctor or allied health professional.

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