Diagnosis. Doctors or dentists can easily diagnose dry mouth. Typically, your doctor or dentist will take a medical history, including medications you are taking, and examine your mouth. Blood tests may be ordered to rule out conditions that cause dry mouth as a symptom. Your doctor may also run tests to ensure your salivary glands are working properly or if you may have a condition called Sjogren’s syndrome, which is characterized by dry mouth and eyes.