The kidneys try to filter out the extra glucose in the bloodstream. This causes glucosuria (too much sugar in the urine). The extra glucose going through the kidneys causes more urine to be created. When a person urinates more, they lose more electrolytes, like sodium and potassium. Without enough electrolytes, the heart, muscles, and nerve cells cannot work properly. Also, eventually, the kidneys can fail because they are overworked by the amount of glucose they are trying to filter.