Step 4: Read and complete the decision guide to learn more about your symptoms.
Dry Mouth and Excessive Thirst
Okay. One relatively common cause of mouth dryness or excessive thirst is poorly controlled diabetes. It's probably related to the frequent urination and mild dehydration that can develop if blood sugar is high; closer control of your blood sugar could improve the oral dryness you describe. Talk with your doctor about whether tighter blood sugar control would make sense for you.
Speaking of dehydration, now comes a related question.
Dehydration is a term that means "too little water" and is common among persons with diarrhea, vomiting, fever, or poorly controlled diabetes, or those who take diuretics (water pills). Exercise in hot, humid weather is another common cause. In addition to mouth dryness, symptoms of dehydration include thirst, a dizzy feeling when arising, headache, and fatigue.
Based on this information, do you think you may be dehydrated?