Sometimes the symptoms are interconnected. When the circulation is poor or compressed, the nerves fire off as lower oxygen and glucose occur and impair their metabolisms.

Metabolic byproducts of energy production then will build up and those will cause the nerves to fire as well.

Dr. Oz calls this "fizzing" at the nerve endings (from one of his shows I happened to watch). I am not sure that is an accurate description.

There are pain receptors in the tissues and spinal cord called NMDA receptors, and they fire off too much when stimulated by aspartate and glutamate. They fire using calcium, and magnesium tends to block them.

http://en.wikipedia.org/wiki/NMDA_receptor

http://www.medscape.org/viewarticle/567856

This last link may require you to join Medscape, but that is free, and easy. There are many good medical articles on Medscape so it is worth belonging to.

Circulatory problems result in changes in color and temperature of the feet and hands. This can then affect the nerves. However, longstanding nerve damage, will result in poor circulation because some nerves affect the blood flow. Sometimes it is difficult to separate those effects out from each other.

If you smoke, then yes, circulatory problems can result from that. It is called peripheral artery disease (PAD) and more common in males that smoke, than females.