Why does high blood sugar cause a problem?

Due to higher blood glucose, the blood becomes viscous (i.e. thicker) and there is difficulty in this thick blood to pass through the small blood vessels in the eye and kidneys. That’s why eye and kidney damage is common amongst diabetes patients. The heart also finds it more difficult to pump thick blood and so the blood pressure also rises as the heart needs to pump more strongly. Hence, hypertension usually follows the diagnosis of diabetes in patients. Sugar is the ideal food for bacteria. Hence, if there is an infection or wound, in diabetics it takes ages to heal as the blood sugar is high and that is the best growth factor for bacteria. We notice that many antibiotics appear to be ineffective in diabetes patients.