Many medical professionals used to think that dry mouth is a normal part of aging. Now they already know that it is not true. Adults and older people that are in good health should not have problems with saliva. Dry mouth occurs when salivary glands do not properly work. Mouth dehydration can make eating, swallowing and speaking difficult. Added to that, dry mouth can also add to the risk of tooth decay and gum infection. Certain medicines, numerous disease and medical treatments can also cause the mouth to become dry. If you think you have dry mouth, talk with your dentist or doctor to find out why. Drink extra water to prevent dryness. Make sure that you cut back on sugary snacks, drinks that have caffeine or alcohol, and tobacco.