What Are the Causes of Dry Mouth & Thirstiness?

Dry mouth and thirstiness are conditions that result from a deficiency of saliva in the mouth. Although dry mouth and thirstiness can sometimes lead to more serious health problems, such as tooth decay or dehydration, they usually can be treated if your doctor knows their cause.

Diet

• Sometimes spicy meals or foods with a high salt content can cause dry mouth and/or thirstiness, according to the University of Maryland Medical Center. Some people develop one or both of the conditions because alcohol or tobacco products cause them to produce less saliva, according to MedicineNet.

Medications

• Anticholinergics, decongestants, antihistamines, muscle relaxants, Parkinson’s disease drugs, antidepressants, diuretics, demeclocycline and phenothiazines sometimes cause dry mouth and thirstiness.

Illnesses

• Certain health problems, such as dehydration, diarrhea and vomiting, can cause people to feel excessively thirsty and/or develop dry mouth, according to MedlinePlus. Infections and burns can sometimes result in a deficiency of body fluids, which can lead to excessive thirst, according to MedlinePlus.

Diseases

• Diseases that can cause dry mouth and/or thirstiness include diabetes insipidus, Sjogren's syndrome, Parkinson’s disease, HIV or AIDS, kidney or liver failure, Alzheimer’s disease, anemia, rheumatoid arthritis, hyperthyroidism, hyperadrenalism and hypernatremia.

Other Causes

• Chemotherapy drugs and radiation treatment can sometimes cause dry mouth and/or thirstiness, according to MedicineNet. Damage to nerves, located in the head or neck, that help facilitate saliva production can cause dry mouth, according to the National Institute of Dental and Craniofacial Research.