We've all experienced a dry mouth at one time or another. Factors such as stress, anxiety and dehydration can produce that dry-mouth feeling when your saliva temporarily stops flowing. My nurses get it each time I call them into the office!It's a different story when it persists over time. As saliva is our natural protective agent chronic dry mouth, known as xerostomia, can cause problems in its own right. It can also be a symptom of other, more serious, conditions.While we take saliva for granted—you certainly miss it when it's gone! Saliva has many important roles to play in keeping our mouth functioning and healthy. For example, it helps to moisten food to make it easy to chew and swallow, aids in the tasting of food, helps our digestive processes to start, and it's the first line of defence in our immune system.An interesting point with Xerostomia is that it is subjective—meaning I can't diagnose it unless you complain about it. Even more interesting is most sufferers wont notice they have dry mouth until their saliva flow has dropped by fifty per cent.Xerostomias actual definition is the feeling of a dry mouth and may actually be present with normal levels of saliva. While Xerostomia is a symptom, not a disease in itself, we can still test for low levels of saliva and do so at every examination. It is actually very common and may simply be related to a mouth-breathing habit (when sleeping) or dehydration… do you drink 2-3 litres of water each day?Xerostomia is frequently caused as a reaction to medications. In fact, dry mouth is a side effect of over 500 different drugs. The common medicinal culprits include antihistamines, anti-depressants, anti-hypertensives, (virtually anything with an 'anti' in front of it), and some beta-blockers, diuretics and some over-the-counter cold remedies.It has been said that if you take three or more types of medication, you will most likely have dry mouth as a side effect. For this reason, adjustment and management of prescribed medications should be considered when treating for xerostomia. This is also why dry mouth is often erroneously thought to be a side effect of old age. It isn't, but because older people typically take more medication than the rest of the population, dry mouth is a more frequent complaint among the elderly.Another, and more serious, cause for concern is when xerostomia appears as a symptom of other conditions. Sjögren's syndrome is one such disease which results in autoimmune damage to the glandular tissues—meaning the body's immune cells attack the tear and salivary glands. Dry mouth can also be a result of diabetes, or it may indicate an underlying metabolic or hormonal problem. Systemic illnesses such as hypothyroidism, rheumatoid arthritis, lupus, hepatitis C and renal failure are known to produce symptoms of xerostomia. If these conditions are suspected, they must be identified and treated for the overall health of the patient, as well as for relief from xerostomia.If these factors are addressed and xerostomia is still present, treatment options include specific medications that may be prescribed to increase the flow of saliva. Patients with xerostomia can get relief by sipping sugar-free, noncarbonated beverages, chewing on gum that contains xylitol, and using a special mouthwash to lubricate and soothe the oral tissues.Xerostomic patients should take good care with their oral health. Xerostomia can lead to an increase in dental cavities, bad breath, and infections in the mouth that could become serious if not treated. Acidic beverages are also harder to buffer and can hence lead to quite severe erosion. For this reason, we recommend that patients with xerostomia get regular check-ups before minor issues become major ones.