Numbness in the extremities is commonly associated with diabetic neuropathy. The occurrence of diabetic neuropathy correlates with the state of blood glucose control, but there are no specific values to indicate how high blood glucose can cause numbness in the extremities. Some patients with long-standing diabetes can develop numbness in the extremities even with good glycemic control. Some newly diagnosed diabetic patients with very high blood glucose do not show symptoms of numbness in the extremities. Therefore, blood glucose is not the only factor associated with diabetic neuropathy. In addition to blood glucose control, the duration of diabetes, insulin resistance, and chronic low-grade inflammation are all closely associated with diabetic neuropathy.