What does the renal threshold of 140-160 mg/dl indicate?

The renal threshold of 140-160 mg/dl indicates the glucose reabsorption limit. This is the concentration range at which the kidneys begin to lose their ability to reabsorb glucose from the renal tubules back into the bloodstream. Below this threshold, glucose is typically reabsorbed efficiently; however, once blood glucose levels exceed this range, the excess glucose remains in the urine, leading to glucosuria. This phenomenon is especially relevant in conditions such as uncontrolled diabetes mellitus, where elevated blood sugar levels can surpass this threshold, resulting in glucose being present in the urine. Understanding this threshold is crucial for assessing kidney function and monitoring metabolic disorders.