Dry mouth or xerostomia is a result of reduced or absent saliva flow. Most people have experienced the temporary sensation of "drying up" when nervous, for example when giving one's first public speech. This is a normal reaction. Dry mouth may also be a symptom of dehydration caused by, for example, vigorous exercise or insufficient fluid intake on a hot day.
Causes of Dry Mouth
The causes of chronic dry mouth include drugs, disease and radiotherapy. Reduced flow of saliva is a side effect of many medications (e.g., those used to control high blood pressure, anti-Parkinson drugs, anti-anxiety agents, antihistamines, diuretics, sedatives) and of some systemic diseases and conditions (e.g., Sjögren's syndrome, systemic lupus erythematosus, rheumatoid arthritis, diabetes mellitus, nutritional deficiencies, depression).Though not directly age-related, dry mouth is more commonly a complaint of older people, who tend to take more medications.
While more than 50% of adults surveyed in 2000-2002 reported having some experience of dry mouth, dry mouth on a regular basis was reported by 12% of older people (aged 65+) compared to only 5-6% among younger adults (aged 16-24 and 35-44).11
The feeling of a dry mouth is a particularly uncomfortable one and often gives rise to difficulty in speaking and eating and can have a major negative impact on a person's quality of life.
Reduced saliva flow can also give rise to an increased incidence of dental decay, gum disease and oral infection (e.g., candida albicans).Radiotherapy to treat cancer in the head and neck area may cause salivary flow to stop altogether, either long term (permanent) or for periods of up to three months (temporary). It is essential that people about to undergo such treatment are informed of the increased oral health risks associated with the reduced saliva flow that may result from their treatment, and are advised of the management measures they can take to
minimise the detrimental effects of dry mouth.
People with dry mouth lose the protective effect of saliva in preventing dental caries and trauma to the oral mucosa. Where dry mouth is medication induced, the prescribing doctor should be consulted about possible alternative drugs which may not have the same xerogenic or mouth drying side effect. For many people, the underlying cause of dry mouth cannot be prevented and management of the problem is the best option. Management involves making the person comfortable by providing oral lubricants (saliva substitutes), and preventing disease through the use of fluoride mouthrinses and mouthrinses to control plaque. People with dry mouth should be careful not to suck sweets (e.g., mints, boiled sweets) regularly. Although sucking sweets may give temporary relief, it will cause severe dental caries in the absence of saliva. Frequent consumption of drinks sweetened with sugar (e.g., soft drinks, tea) should also be avoided. Even sugar-free sweets and drinks can be problematic due to their acid content which is erosive to the teeth, especially in the absence of saliva. The frequent sipping of iced water may provide some relief and can be recommended. Acupuncture is an alternative therapy that may also bring relief to those with dry mouth. Nowadays there are many saliva substitutes or oral lubricants on the market, generally available through pharmacy outlets; these can be effective in reducing the unpleasant side effects of reduced flow of saliva. Saliva stimulants have also been developed for those with some remaining salivary gland function; these are available on prescription but do have some side effects which should be discussed prior to use.