Saliva is a watery fluid in the mouth that is secreted by 3 major glands: the Parotid glands, the Submandibular glands, and the Sublingual glands. Saliva performs vital functions in the oral cavity including: 

• lubrication of the mouth and throat

• facilitating swallowing by softening and breaking up food during chewing

• breaking down food in the stomach by means of the enzyme Amylase

• keeping the mouth clean

• reducing the risk of tooth decay and gum disease

• maintaining the pH levels in the mouth balanced 1 

Symptoms of dry mouth include:

• a feeling of stickiness in the mouth

• difficulty chewing, swallowing, talking or tasting

• burning sensations in the mouth or throat

• dry throat

• chapped lips

• sores in the mouth

• halitosis (bad breath) 

• frequent mouth or throat infections 2 

Dehydration reduces the amount of liquids in the body and causes the salivary glands to produce less saliva which results in dry mouth. Common causes of dehydration include:

• Not drinking enough liquids throughout the day

• Excessive sweating 

• Vigorous exercise

• Hot weather

• Diarrhea and vomiting

• Fever

• Frequent urination

According to WebMD the following suggestions can help reduce dehydration:

• Drink fluids (e.g. water, sports drinks, milk, broth) all day even if you don't feel thirsty. Once feelings of thirst begin, your body is already dehydrated

• Drink 6-8 cups of fluids a day. Increase amount during hot weather or if you have a fever

• Eat a balanced diet that includes fruits and vegetables and don’t skip meals

• Limit coffee, alcohol, caffeinated drinks and high-protein drinks 3

The body's sympathetic nervous system produces thicker saliva as a result of stress and nervousness. 4 

The sympathetic nervous system releases norepinephrine when its "flight or fight response" is activated. According to Yoshiwaka et al., "norepinephrine (NE), released from postganglionic sympathetic nerve endings within the salivary glands, has an effect on the salivary glands primarily stimulating protein secretion. Norepinephrine activates alpha-adrenergic receptors in blood vessels and beta-adrenergic receptors in acinar cells, respectively, causing a decrease in the blood flow and an increase in the protein secretion, resulting in the secretion of viscous saliva with low water content and high protein content." 5 The chemicals released in our bodies when we are stressed or feel nervous cause less saliva to be produced and at the same time cause more proteins to be released in what little saliva is made. This causes thicker saliva and can cause xerostomia. 

Feelings and conditions that can trigger this stress response include:

• stress

• depression

• anxiety

• nervousness

Certain medications can cause dry mouth as a symptom such as:

• Antianxiety drugs

• Antidepressants

• Antihistamines

• Decongestants

• Pain medications

• Chemotherapy drugs

• High blood pressure medications

• Parkinson’s disease medications

• Anticholinergics 6

To eliminate xerostomia you can speak to your healthcare provider about reducing the dosage or switching to an alternative medication.

Certain health conditions can results in dry mouth such as:

• Salivary stones 6

• Diabetes

• Stroke

• Alzheimer’s disease

• Sjögren syndrome

• HIV/AIDS 7

Speak to your healthcare provider if you experience chronic xerostomia that does not go away with home care, over the counter products, or by switching medications.

If OTC products and home self-care measures do not alleviate the xerostomia, your physician or dentist may prescribe Rx products. Your physician may also choose to reevaluate prescribed medications causing the dry mouth.  Webdmd.org lists possible Rx medications including: 

• Pilocarpine - 5 mg 3 times a day. This drug should not be taken if you have: uncontrolled asthma, acute iritis, or angle-closure glaucoma. 14 

• Cevimeline - 30 mg 3 times a day. This drug should not be taken if you have: uncontrolled asthma, narrow angle glaucoma, or acute iritis. 15

• Bethanechol Chloride - 10-50 mg 3-4 times a day.  This drug should not be taken if you have:  "hyperthyroidism, peptic ulcer disease, epilepsy, asthma, pronounced bradycardia or hypotension, vasomotor instability, coronary artery disease, or parkinsonism, mechanical obstruction of the GI or GU tract, decreased strength or integrity of the GI or bladder wall; have had: urinary bladder surgery, GI resection and anastomosis, possible GI obstruction; bladder neck obstruction, spastic GI disturbances, acute inflammatory lesions of the GI tract, peritonitis, marked vagotonia." 16