My friend Lao Li, who had been urinating a lot and suffering from irritable thirst in recent months, was diagnosed with diabetes soon after he came to the hospital to see me for an examination. Subsequently, along with each blood sugar test, urine sugar was also measured and it was found that when blood sugar rose significantly, the “+” in urine sugar also increased, and when blood sugar was in the normal range, urine sugar was negative. Therefore, under the doctor’s guidance, Lao Li controlled his daily diet and took only a small amount of hypoglycemic drugs, and his blood sugar stayed in the normal range and he did not have thirst and polyuria. I told him that he did not need to draw blood too often to review his blood sugar, but just use urine test strips to measure urine sugar to indirectly monitor the fluctuation of blood sugar and provide a basis for the increase or decrease of glucose-lowering medication. The Fourth Military Medical University Tangdu Hospital, Department of Nephrology Sun Ridge Feng Lao Li disciple Xiao Li is very interested in the master’s method of measuring urine sugar, and the master asked for two pieces of test paper, to their own urine test negative, quite happy, for his pregnant wife to test the urine, the test paper showed positive urine sugar, shocked, Xiao Li immediately shouted: “Oh my God! Oh no, my wife has diabetes, what should I do with the baby?” The next day, Li took his apprentice couple that rushed to the hospital to find me. After examination, Xiaoli wife’s blood sugar is normal, postprandial blood sugar is also within the normal range, denying the diabetes. But why was the urine sugar “positive”? This condition is called renal diabetes. There are various causes of renal diabetes, and one of them is called renal diabetes during pregnancy. Because the pregnant woman’s body undergoes a series of physiological changes to adapt to the needs of pregnancy, such as an increase in the volume of blood circulating throughout the body, the blood flow of the kidneys also increased, the filtration of glucose increased, coupled with certain changes in the function of the renal tubules during pregnancy, such as a reduction in the reabsorption of glucose and amino acids, although the concentration of glucose in the blood is normal, but still beyond the renal threshold, so urine sugar positive, this situation is not pathological, is This condition is not pathological and is called physiological urine sugar, after the delivery of the fetus, it can return to normal and does not need to be treated with drugs. In fact, in addition to gestational diabetes, there are also congenital or familial renal diabetes, also known as benign diabetes, is the cause of unexplained renal tubular reabsorption of glucose due to reduced function. In addition, some rare diabetics with congenital defects in both jejunal and renal tubular epithelial transport of galactose and glucose have been identified, called congenital glucose DD galactose intestinal DD renal tubular malabsorption syndrome. Renal glycosuria also often occurs in chronic kidney disease or renal tubular disease, because these diseases damage the proximal tubule, so that its reabsorption capacity is reduced, and the excretion of sugar is increased. Therefore, the discovery of renal diabetes is not certain to be physiological, benign, not careless, but also need to rely on doctors to carry out a systematic examination to determine neither elevated blood sugar, nor kidney disease, before you can rest assured.