How does glycosuria affect body functions?

Not directly. Glycosuria or sugar in the urine does not have any direct affect on body functions. However, there should not be any sugar in the urine unless there is loss of kidney function and/or high levels of sugar in blood (e.g. Due to diabetes). Excessively high blood sugar can be very serious, leading to neurological deterioration, nausea, vomiting, abdominal pain and even stupor or coma.
Diabetes. Glucosuria suggests that you are at risk or diabetes. High blood sugars affect the body in many ways. Please see your primary care doctor for an evaluation - usually a blood test to see your blood sugar averages over time, .