India, Feb. 11 -- Type 2 diabetes can go undetected for years, often as it people do not display the classic symptoms of thirst and urinating more often. But check for these signs that could indicate testing makes sense. Berlin (dpa) - You've got this persistent tingling sensation or numbness in your feet, so you go to a doctor and are probably surprised to learn you have diabetes. You shouldn't be, as it's not uncommon for this incurable, chronic, metabolic disease to cause health issues before it's detected, such as peripheral nerve damage or blurred vision due to damaged blood vessels in the eyes. Diabetes is characterized by high blood sugar (glucose) levels due to insufficient production or function of insulin, a hormone produced by ...