What Causes Dry Mouth, And What To Do About It

Dry mouth, a condition that the medical literature terms xerostomia, is a common complication of poorly controlled type 2 diabetes and autoimmune conditions such as lupus, rheumatoid arthritis, scleroderma, and Sjögren's syndrome.

Chemotherapy and radiation therapy often cause dry mouth. It is also a frequent side effect of medications used to treat anxiety, depression, Parkinson's disease, Alzheimer's disease, asthma, coughs, cold, stuffy nose, and allergies. Older people are especially likely to get dry mouth, but this is because of medication use, not because of their age.

Dry mouth is aggravated by smoking, drinking, and smoking marijuana, and an especially unpleasant form of dry mouth known as "meth mouth" frequently occurs in people who use methamphetamines. People who have trouble breathing through their noses at night or who have sleep apnea may suffer "morning mouth" from overnight desiccation of the lips, gums, and mucous membranes lining the mouth.

Dry Mouth Isn't Just Unpleasant

People who have dry mouth don't just suffer bad breath and dry and chapped lips. A dry mouth is especially at risk for infection. Without a constant flow of saliva over the teeth, cavity-causing Streptococcus mutans bacteria can accumulate and eat holes through the enamel. The yeast infection Candida albicans can grow on the tongue and palate, causing an unpleasant condition known as thrush. And dry mouth makes eating and talking more difficult.

Dry mouth interferes with good nutrition.

One of the ways the body manages to get complete protein (the full complement of essential and non-essential amino acids) from food is by constantly digesting its own saliva. In fact, more than 50% of the protein absorbed by the body is circulated through the salivary tract, storing essential amino acids so the body does not have to break down muscle tissue and white blood cells to get the building blocks of proteins to keep vital organs in good repair.

When there isn't enough saliva production, the body has to get all of its amino acids from protein foods, and these protein foods have to be eaten each and every day. Oddly enough, dry mouth can result in muscle loss.

What Causes Dry Mouth?

Medications for allergies, asthma, Alzheimer's, and Parkinson's disease, as well as cigarettes, marijuana, heroin, and methamphetamines, interfere with the signals sent by the parasympathetic nervous system that tell the salivary glands to release saliva. Except in the case of "meth mouth," when the medication or recreational drug is discontinued, the salivary glands resume normal function and dry mouth disappears, although halitosis may persist until the bacterial film that causes it is removed from the gums and tongue. The problem is that many people who use these medications have to have them on an ongoing basis.

When dry mouth is caused by autoimmune disease, however, the underlying problem usually is the destruction of the salivary glands by the immune system itself. When this happens, dry mouth becomes a permanent condition that requires life-long oral health care.

Ten Things You Can Do About Dry Mouth

Fortunately, dry mouth is usually not especially hard to treat. Here are ten things you can do to treat dry mouth and keep your breath fresh and your mouth comfortable.

1. Sip small amounts of non-carbonated beverages throughout the day.

The best moisturizer for the mouth is water. Small sips of water throughout the day help keep the mouth moist.

Contact of liquid with the mouth is what makes the difference. Drinking beverages fast won't correct dry mouth. Minimize consumption of carbonated beverages, especially sugar-sweetened carbonated beverages, to prevent damage to tooth enamel.

2. Try artificial saliva.

Artificial saliva is designed to keep the mouth moist with a mixture of water and a surfactant that helps it coat and soothe the gums, tongue, and mucosal membranes. In the US, EU, Canada, and Australia, artificial saliva is available without a prescription, although it can be hard to find on store shelves. On retailers offer brands of artificial saliva such as Biotene, Oasis, Dry Mouth Mist, and Xlear, in rinses, sprays, and lozenges.

3. Chew gum sweetened with xylitol.

Chewing gum stimulates salivation. The natural sweetener xylitol (extracted from certain kinds of tree bark and from corn cobs) does double duty adding taste to the gum and killing step bacteria that can cause cavities and sore throat. Xylitol chewing gum also helps prevent ear infections.

4. Try a carboxymethyl cellulose saliva substitute.

If you have dry mouth that is caused by Sjögren's syndrome, rheumatoid arthritis, or lupus, carboxymethyl cellulose may be especially helpful. This compound is made from wood bark treated with an acid. It coats the mouth and locks water in place. Carboxymethyl cellulose is an approved food additive in the US and EU, often used to make ice cream creamier. It's available over the counter in most countries; ask your pharmacist where to find it on the shelf.

5. Ask your doctor about Salagen.

Salagen is the brand name for the generic drug pilocarpine, long used to treat problems with circulation in the mouth and eyes. It's only available with a prescription in most countries. This product acts on the nerves leading to the salivary glands to stimulate salivation. It also lowers eye pressure, so consult a physician before trying it.

6. Ask your doctor about Evoxac. 

Evoxac is the brand name for the generic drug cevimeline. Like Salagen, it stimulates salivation by acting on the nerve fibers that lead to the mouth, but unlike Salagen, it cannot be used by people who have glaucoma or asthma. 

7. Avoid hot beverages.

Hot beverages of all kinds cause flaking of the mucous membranes lining the mouth and covering the bottom of the tongue. Flaking leads to an uncomfortable sensation called "cotton mouth." If you have to have your morning coffee, drink a glass of water a few minutes later as a chaser.

8. Avoid alcohol, especially hard liquor.

Like hot coffee, alcoholic beverages cause flaking of the mucous membranes lining the mouth. Any beverage that is over 92 proof will kill the outermost cells of the oral mucosa on contact, making dry mouth much worse.

9. Eat your food with a grain of salt.

If you are not on a low-sodium diet, adding granular crystals of salt to your food will stimulation salivation. It also helps to add a little acid, such as a twist of lemon juice, to a soft food to help your mouth water as you eat. Just avoid adding so much salt or lemon juice that you irritate your mouth.

10. Avoid dry, salty snack foods, such as chips (crisps) and crackers.

Salty snack foods stimulate salivation, but they may injure the lining of a dry mouth. Get your "salt fix" by adding visible crystals of salt to soft foods, rather than eating dry, salty snack foods.