Here is a little bit more about the exact science of the phenomenon. Normally when you get cold or stressed your body limits blood supply to your extremities by narrowing the smaller arteries. This retains heat and uses less energy. In people with Raynaud’s the body overreacts and the arteries go into vasospasm, the vessels narrow dramatically and may also thicken slightly, cutting off almost all blood flow. This gives us a lovely show of color change in the affected area varying from a corpse-like white color to a deep purple, depending on the amount of blood your body is letting in. The affected areas also go incredibly numb and can become hard to move. With prolonged exposure to cold or stress it often becomes very painful. For me, being in high school, after walking from my car maybe a hundred feet in the cold to my first class my fingers would be so numb that I couldn’t write the entire period. I would have to return once my fingers had thawed out to make up any tests or quizzes that I couldn’t take in the morning. Talk about a pain. You may have Raynaud's in all of your extremities, or you may just suffer from it in one or two areas. It is also possible to have it in only a part of didgit.
About five percent of the general population suffers from Raynad’s. But it is more common in women than in men. In surveys of women ages 15-40 as high as fifteen percent were found to have Raynaud’s, this may be due to influence of estrogen on the vascular system. Raynaud's is also more prevalent in areas with colder climates.
There are two types of Raynaud’s; primary and secondary. Primary is just the numb fingers and toes, without an underlying cause. Secondary Raynaud’s is caused by other conditions such as: Scleroderma, Lupus, Rheumatoid arthritis, Sjogren's syndrome, carpal tunnel syndrome, repetitive trauma, or other diseases of the arteries.
