High blood sugar, also known as hyperglycemia, is commonly associated with conditions like diabetes. It's a well-known fact that elevated levels of glucose in the bloodstream can often manifest in the urine, leading to a condition called glycosuria. When someone has high blood sugar but doesn't pass sugar in their urine, it can be confusing and needs to be looked at more closely. There are several reasons why someone might have high blood sugar levels without sugar appearing in their urine: Renal threshold: Each person has a renal threshold, which is the blood glucose level at which the kidneys start to excrete glucose into the urine. Normally, this threshold is around 180 mg/dL. If blood sugar levels remain below this threshold, all glucose is reabsorbed by the kidneys, and no sugar appears in the urine. Some individuals may have a higher renal threshold, meaning that their kidneys don't start excreting glucose until blood sugar levels are very high. Early stages of diabe...