Dry mouth and thirstiness are conditions that arise from a deficiency of saliva in the mouth. Drinking a lot of water is usually healthy. However, the urge to drink too much may be a symptom of a serious medical condition. The first thing that comes to mind for the reason of your being thirsty all the time is diabetes. You should have it checked out. A simple glucose tolerance test can tell you if it is diabetes. Of course, excessive thirst has other causes. Having too much spice or sodium (salt) in your diet obviously makes you thirstier than normal. It can be dehydration, which is unlikely in your case. Another cause may be Sjogren's Syndrome, a chronic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva. One of its symptoms is typically dry mouth that makes you feel thirsty all the time. A list of other common diseases that have the same symptom includes hyperthyroidism, HIV or AIDS, Parkinson's disease, kidney or liver failure, anemia
, Alzheimer's disease, rheumatoid arthritis
, hyperadrenalism and hypernatremia. Certain medications including the over-the-counter drugs can sometimes cause dry mouth and thirstiness. It is not possible to establish your diagnosis online. I would recommend that you see a primary care doctor
to get diagnostic tests to find out what is causing your excessive thirst, whether or not it is simply from diet or a cause of a serious condition.