There are several causes of dry mouth, also called xerostomia.
These include :-
Side effect of certain medications: Dry mouth is a common side effect of many prescription and nonprescription drugs, including drugs used to treat depression, anxiety, pain, allergies, and colds .
Side effect of certain diseases and infections: Dry mouth can be a side effect of medical conditions, including Sjögren's syndrome, HIV/AIDS, Alzheimer's disease, diabetes, anemia, cystic fibrosis
, rheumatoid arthritis
, Parkinson's disease, stroke, and mumps.
Side effect of certain medical treatments.:Damage to the salivary glands, the glands that produce saliva, for example, from radiation to the head and neck and chemotherapy
treatments for cancer, can reduce the amount of saliva produced.
: Dry mouth can be a result of nerve damage to the head and neck area from an injury or surgery.
Dehydration: Conditions that lead to dehydration, such as fever, excessive sweating
, vomiting, diarrhea, blood loss, and burns can cause dry mouth.
Surgical removal of the salivary glands.
Lifestyle. Smoking or chewing tobacco can affect saliva production and aggravate dry mouth. Continuously breathing with your mouth open can also contribute to the problem.
Steps you can take that may help improve saliva flow include:-
Sucking on sugar-free candy or chewing sugar-free gum.
Drinking plenty of water to help keep your mouth moist.
Protecting your teeth by brushing with a fluoridetoothpaste, using a fluoride rinse, and visiting your dentist
Breathing through your nose, not your mouth, as much as possible.
Using a room vaporizer to add moisture to the bedroom air.
Using an over-the-counter artificial saliva substitute.
Hope I have answered your query.