Dry mouth - Xerostomia
Saliva is manufactured in the mouth by three sets of salivary glands, located above the tongue, on the floor of the mouth, and above the angle of the jaw. When true xerostomia occurs, both the mouth and lips are dry. Because the teeth and gums are meant to be bathed constantly in saliva — which has antibacterial properties — the shortage of this fluid can contribute to bacterial overgrowth. In turn, this can promote a build up of bacterial plaque, bad breath, tooth decay, and gum disease. A severe dry mouth also impairs a person's enjoyment of food.
Mild symptoms of a dry mouth often go unnoticed by the individual. A dentist may be the first one to observe a change in the quality or quantity of a patient's saliva. Sometimes, increased urination is the first symptom the individual notices, because a dry mouth promotes thirst and an increased intake of fluids.
Saliva production decreases with age. The most common causes of dry mouth, however, are side effects of various medications. A number of diseases may also reduce saliva production.
Causes of dry mouth
Excessive thirst and a dry mouth are among the many common symptoms of a hangover after drinking too much alcohol. After a bout of heavy drinking, the person typically wakes up thirsty, with a dry mouth and malodorous breath. Alcohol increases the flow of urine, which reduces body fluids and results in thirst and reduced flow of saliva.
A dry mouth is often a warning sign of dehydration, or excessive loss of body fluids. Dehydration, which is particularly dangerous in an infant, may be caused by diarrhea, prolonged vomiting, or heatstroke. It also can result from inadequate fluid intake during prolonged exercise.
Although the salivary glands can become infected by a wide variety of viruses or bacteria, the most common cause is mumps. In this disease, the salivary glands and the lymph nodes in the neck are swollen and painful. In severe cases, the salivary glands may be permanently scarred and cease to function. A bad sore throat, an upper respiratory infection, or any illness that produces a high fever can also result in dry mouth.
A wide variety of medications can produce dry mouth as a side effect. The most common over-the-counter culprits are cold or allergy pills that contain antihistamines. These drugs have a strong anticholinergic effect, which reduces the secretion of saliva. Other drugs that reduce saliva production include sleeping pills, tranquilizers, and certain antidepressants. Some drugs used in cancer chemotherapy can also cause dry mouth.
Rheumatoid arthritis, scleroderma, and systemic lupus erythematosus are all chronic illnesses in the rheumatic family of diseases. They are believed to be autoimmune disorders in which the immune system attacks healthy body tissue and organs as if they were foreign invaders. In addition to diverse other symptoms, all three cause joint stiffness and pain and may precipitate dry mouth by unknown mechanisms. In lupus, dry mouth problems may be worsened by frequent mouth ulcers.
Salivary gland disorders
Hard particles or "stones" sometimes form in the salivary glands and block the duct through which saliva normally enters the mouth, a condition called sialolithiasis. In other instances, a tumor, which is usually benign, may block the flow of saliva.
Radiation therapy for treatment of cancers of the head and neck reduces the production of saliva and carries a high risk of mouth sores and other oral problems.
Sjogren's syndrome is a chronic inflammatory disorder that can cause dryness of mucous membranes throughout the body, including the mouth, eyes, nasal passages, bronchi, and vaginal tract. Dryness in the respiratory tract can promote lung infections and severe pneumonia. It may occur alone or in conjunction with other rheumatic problems, such as rheumatoid arthritis, scleroderma, or lupus.
Advice about dry mouth
- Don't smoke, which worsens a dry mouth.
- Don't turn to hard candy or sugary soft drinks to allay thirst and a dry mouth because they promote further tooth decay. Instead, suck ice chips or increase the intake of water, seltzer, or diet sodas.
- To help promote saliva production, suck a thin slice of lemon or chew sugarless gum.
- Maintain a scrupulous program of dental self-care, including twice daily brushing and daily flossing.
- See a dentist frequently for cleanings and prompt treatment of any dental or gum problems that arise.
- Avoid mouthwashes that contain alcohol, which has a further drying effect on oral tissues.
- Ask a dentist or pharmacist about over-the-counter products to help alleviate dry mouth, such as the Biotene line of antibacterial toothpaste, mouthwash, and chewing gum. Such products promote saliva production and reduce bacterial growth.
- Ask a dentist or doctor about Oral Balance moisturizing gel or other saliva substitutes.