The proximal convoluted tubule is lined by simple cuboidal brush border epithelium which increases the surface area for reabsorption. Nearly all of the essential nutrients and 70-80 percent of electrolytes and water are reabsorbed by this segment. Glucose is completely reabsorbed from PCT under normal conditions. But in conditions like diabetes mellitus glucose is not completely reabsorbed in the renal tubule because of which glucose is found in urine. The presence of glucose in urine is called as glycosuria.