A healthy mouth produces over 6 cups of saliva every day. Although its primary function is to aid in tasting and eating food, your mouth remains moist whether you're eating or not. A wet mouth means your saliva glands are functioning properly and is a sign of overall health. If your mouth remains dry no matter how much you drink, your body is sending you a signal that all is not well.

A Little Anatomy

As their name implies, your salivary glands produce saliva. These glands are located in your mouth and throat and each produces a different type of saliva. In your cheek near your ear are the parotid glands that produce a watery saliva that is delivered to the area around your upper teeth. Under your tongue is the sublingual gland that makes a saliva that contains a large amount of mucous. Near your jaw are the submandibular glands that secretes a mixed saliva. Other smaller glands dispersed through the mouth also produce saliva.

You Have No Control

All of your salivary glands are controlled by the autonomic nerve system, which means you have no direct control over how wet with saliva your mouth is. Like the beating of your heart, you can't stop your salivary glands from working, and the glands will automatically work harder depending on need. When signals, such as the smell of food, hit the brain, the salivary glands produce more saliva to prepare your mouth for eating. When food isn't present, healthy salivary glands produce enough saliva to keep your mouth continually moist.

The Need for Moisture

Your saliva helps you process food in many ways. As you chew, saliva moistens food, lubricates your throat to help you swallow and provides the first dose of enzymes to digest your food. You need your mouth to stay moist even when you're not eating because saliva acts like a washing machine for your mouth. Saliva continually washes away food particles and keeps the bacteria in your mouth from taking over. A moist mouth and throat also aids in speech and breathing. If you've ever had a dry throat from a cold, you'll remember how uncomfortable breathing and talking became.

When Things Go Wrong

A dry mouth can be caused by dehydration. When your body doesn't have enough fluids, it slows down saliva production to keep other areas of your body functioning. A dry mouth accompanied by swelling of the salivary glands can signal an infection such as mumps or the flu. Swelling and a dry mouth may also be a symptom of a mineral stone obstructing your salivary glands. If the stone isn't removed, the glands can be permanently damaged. Because swelling and dry mouth are symptoms of tumors or auto-immune disorders, it's vital that you visit your doctor when you experience these problems. Just as a dry mouth is a sign of trouble, overproductive salivary glands also mean you need to get to the doctor. Mouth lesions, neurological disease and problems with the pharynx can leave you drooling.