Diabetes is the “undead cancer”, although it is not “sugar” to talk about, but also enough to make people fear. Therefore, it is important to do a good job of sugar control and not to neglect this work. To confirm the diagnosis of diabetes, a good sugar tolerance test is required. The urine sugar test is a measurement method often used by diabetic patients because it is relatively simple and easy to use, but the urine sugar test is not a complete substitute for blood sugar testing, although it can be fast and convenient, but because of its poor sensitivity, only when a person’s blood sugar level exceeds the renal sugar threshold, this time the urine sugar problem will be reflected, that is, the urine sugar level indirectly reflects the blood sugar It is only qualitative but not quantitative. If urine sugar is present in the usual physical examination, we may be a little alarmed, fearing that it is caused by diabetes. However, it is important to know that high urine sugar does not necessarily mean high blood sugar. The physiological urine sugar is generally transient and temporary, such as the intake of a large amount of sugar in a short period of time caused by diet, as well as in traumatic brain injury, emotional excitement, etc., the temporary increase in urine sugar under stress conditions. Pathological urine glucose can be divided into true, renal or other urine glucose, and must be combined with other glucose testing indicators to consider whether there is typical or completely clear diagnosis of diabetes mellitus. A normal person with undetectable glucose in the urine is a type one urine sugar, but if the glucose level is elevated, the urine sugar will appear as a plus sign. There are three reasons for high blood glucose levels, one: eating too much sugar at one time. Two: Too little insulin secretion. Three: lack of receptors on the cell membrane. The latter two are diabetes. If in doubt, do a glucose tolerance test.