It sounds like you are referring to Raynaud's Disease. It's more common in women than in men and it usually develops in your 20's or 30's. It mostly affects the hands and fingers, however toes, nose and ears can be affected, too.
You will notice that the symptoms come about after exposure to cold or stress. It causes numbing and cold feeling. Your fingers will turn white at first because the blood vessels are being constricted, and then turn a blue color from loss of oxygen. If the area becomes inflamed, they may turn reddish color. Different things can trigger Raynaud's symptoms such as high blood pressure which causes a constriction of blood vessels. It's a good idea to avoid caffeine and nicotine during these times that symptoms are present.
Raynaud's in itself is not usually dangerous, however it should be evaluated by your physician because sometimes Raynaud's symptoms appear when there is a connective tissue disease present such as scleroderma or lupus disease. (Both can be serious.) Your physician may prescribe a beta blocker which is primarily used for blood pressure control or heart arrhythmias as well as other cardiac related problems. Beta blocker work for Raynaud's by helping to dilate the blood vessels allowing an improvement of blood flow.
Please let me know if you need further info or clarification.