What is diabetic neuropathy?

Diabetic neuropathy is the term used to describe the usually chronic damage to nerves that occurs as a result of untreated, or inadequately treated, high blood sugar. It results from a complex sequence of events that leads to damage and destruction of the minute blood vessels that nourish nerves along their course to the region of the body they serve after leaving the spinal canal. Each such nerve is a single cell. The longest nerves, much like long chains, are the most susceptible to damage. If a peripheral nerve (i.e., a nerve cell not contained in the brain or spinal column) emerging from the spinal column and traveling to the toes were the thickness of a piece of string, it would be 3 miles in length! At fre- quent intervals along its length, each peripheral nerve receives nourishment from tiny blood vessels. If any of these tiny blood vessels are irreversibly damaged, that part of the nerve dies and no signals are conducted in either direction along it, i.e., the chain fails at its weak- est link. Although there are a vast number of individ- ual nerve fibers serving any one area of the body, when a sufficiently large  number  get damaged, symptoms will result. Since the  longest  nerve fibers serve the parts of the body that are farthest from the spinal col- umn, it is not surprising that they are the ones  most frequently damaged. Therefore, diabetic neuropathy is most frequently a problem in the feet, hands, and male genitals. The  symptoms  represent  a  spectrum  from those due to injury responses of the non-fatally injured nerves, such as pain, burning, and abnormal sensations such as bunched socks under the feet, to those due to loss of impulses, such as numbness and  unperceived injury  due  to  loss  of  protective  sensation.   This includes inability to perceive heat and sharp pain, lead- ing to burns and puncture wounds. Although the typi- cal            form      of         diabetic           neuropathy       causes  these symptoms, there are a number of other less common forms that  can lead  to  sudden  pain, weakness, and other unsuspected symptoms in almost every region of the  body. Discussion of the  whole range  of these is beyond the scope of this book.