The glomerulus filters 180 liters of fluid per day, and about 99% is reabsorbed by the renal tubules, such as water, potassium, sodium, glucose, amino acids, uric acid, phosphate, bicarbonate, and other substances needed by the body, and the damage necrosis of the renal tubules, diabetic nephropathy and so on, can cause renal tubular reabsorption dysfunction. Causes of renal tubular reabsorption disorder: 1, injury of renal tubules. 2, renal glycosuria, refers to the disease of glycosuria caused by the reduced function of proximal renal tubular reabsorption of glucose under the condition of normal blood glucose concentration or below the normal renal glucose threshold. Clinically, it is divided into primary renal glycosuria and secondary renal glycosuria. Acute tubular necrosis. 4, Diabetic nephropathy and other tubular damage leading to tubular reabsorption dysfunction.