The reabsorption of glucose occurs in the kidneys. Plasma and non-cell parts of the blood enter tubes in the kidneys called nephrons, where waste is filtered out and necessary components, such as glucose, are reabsorbed into the bloodstream.
Transporter proteins in the kidney pull necessary blood components out of the filtrate mixture that flows through the nephrons. The specific transporter that carries glucose also carries sodium for reabsorption. The glucose and sodium pass from the transporter proteins back into the bloodstream through the capillary walls. When blood levels of glucose are high, the transporters do not catch all of the glucose and some passes into the urine. This is common in patients with diabetes.