What could be the cause raynaud's?

Cold and Stress: Doctors don't completely understand the cause of raynaud's attacks, but blood vessels in the hands and feet appear to overreact to cold temperatures or stress. With raynaud's, arteries to your fingers and toes go into vasospasm. Vasospasm narrows your vessels dramatically and temporarily limits blood supply. Secondary raynaud's may be associated with several underlying diseases, usually autoimmune.

BAsic cause: Raynaud's is a disease that is defined by changes in the muscular lining of the arteries in response to temperature. Cold causes constriction (blue) and warmth causes expansion (redness). No specific reason for the muscular lining's reactiveness has been found. Treatments vary from patient to patient but good symptomatic relief is possible. Get to an expert in artery disease for best outcome.