It is thought that high blood glucose levels causes chemical changes in nerves. This impairs the nerves' ability to transmit signals. High blood glucose levels also damage blood vessels that carry oxygen and nutriments to nerves. In addition, inherited factors probably unrelated to diabetes may make some people more at risk than others. Most recently, researchers have all ears on the effects of excessive glucose metabolism on the amount of nitric oxide on nerves.
Nitric oxide dilates blood vessels.
In a person with diabetes, low levels of nitric oxide may lead to constriction of blood vessels supplying the nerve, contributing to nerve damage. Another promising area of research centers on the effect of high blood glucose attaching to proteins, altering the structure of the proteins and affecting vascular functioning. The symptoms of neuropathy depend on which nerves and what part of the body is affected. It can be diffuse, affecting many parts of the body, or focal, affecting a single specific nerve or part of the body. Mild cases may go unnoticed for some time.