The glomerulus filters 180 liters of fluid per day, about 99% of which is reabsorbed by the tubules, such as water, potassium, sodium, glucose, amino acids, uric acid, phosphate, bicarbonate and other substances needed by the body, damage to the tubules necrosis, diabetic nephropathy, etc. can cause tubular reabsorption dysfunction. Differential diagnosis of renal tubular reabsorption disorders: 1. Acute tubular necrosis: Acute tubular necrosis (ATN) is the most common type of acute renal failure, accounting for about 75% to 80%. It is a clinical syndrome caused by various etiologies of renal ischemia and/or nephrotoxic damage resulting in an acute, progressive decline in renal function. The main manifestations are progressive azotemia due to a significant decrease in glomerular filtration rate, and imbalance of water, electrolyte and acid-base balance due to low renal tubular reabsorption and excretion function. According to the decrease of urine output, there are two types: oliguric (anuric) and non-oliguric. Early administration of dialysis therapy for heavy patients can significantly reduce the incidence of infection, bleeding and cardiovascular complications. The prognosis is related to the primary disease, age, early diagnosis and treatment, and whether multiple organ failure is combined. Part of the cause of acute tubular necrosis can be prevented, most reversible, with timely treatment, renal function can be completely restored in a few weeks or months. 2, renal diabetes: renal diabetes is a normal blood glucose concentration and diabetes, fasting blood glucose and glucose tolerance are normal. Various congenital or acquired causes (such as familial renal diabetes and various renal tubular acidosis, etc.) cause renal damage to the proximal tubule, resulting in the renal tubular reabsorption of glucose is reduced, while the glomerular filtration rate is still normal, due to the lowering of the renal sugar threshold and present diabetes, often accompanied by amino acids, bicarbonate and uric acid reabsorption disorders. However, there are some renal diabetic patients can be transformed into true diabetes. 3, diabetic nephropathy: uropathy nephropathy (DN) is a particularly common and more troublesome complication of diabetes. In other words, diabetic nephropathy is one of the most serious complications of diabetes, and is the main cause of end-stage renal disease. Diabetic nephropathy is a major microvascular complication of diabetes, mainly referring to diabetic glomerulosclerosis, a type of glomerulopathy in which vascular damage is the main cause. In the early stage, it is mostly asymptomatic and blood pressure may be normal or high.