Can high sugar levels in diabetics cause frequent urination and dry mouth?

Yes: Please contact your doctor for good blood sugar control and long term sugar level test (hba1c). It's very important to have very good control of diabetes. Uncontrolled diabetic will lead to many medical issues(eye, heart, kidney, leg circulation etc). Please make sure to have yearly eye exam and close follow up with your docs. Exercises and diet helps with better control of diabetes.