Hello! I had gone through your query and understand your concerns. There are many conditions that can cause excessive thirsty, drinking to much water and than frequent urination. If I were your treating doctor I first would rule out Diabetes Mellitus which is the most common cause. I would advise to run a blood sugar test(random or fasting plasma glucose,HbA1c). If this test result normal we can think other possible causes. -Diabetes insipidus is an uncommon disorder characterized by intense thirst, despite the drinking of fluids (polydipsia), and the excretion of large amounts of urine (polyuria). In most cases, it s the result of your body not properly producing, storing or releasing ADH hormone(anti-diuretic hormone), but diabetes insipidus can also occur when your kidneys are unable to respond properly to that hormone.In this case a number of tests are done to confirm the diagnose such as : -Water deprivation test -Urinalysis ( If your urine is less concentrated, meaning the amount of water is high relative to other excreted substances, it could be due to diabetes insipidus. - MRI of the head to look for abnormalities in or near the pituitary gland. I suggest to consult an endocrinologist because you need a complete evaluation in order to sort out the right cause of these symptoms and get the right treatment. Hope my answer has helped. Take care. Dr.Rovena