A disease of the small arteries that carry oxygen-rich blood to the fingers, toes and nose. The arteries narrow when exposed to cold temperature. This decreases blood flow to the affected body part causing it to turn white and blue. The arteries then widen, blood flow returns and the area turns red and throbs. In severe cases the decreased blood flow can cause ulcers and death of the tissue. There are two types of Raynaud's: primary and secondary. Primary Raynaud's occurs without any other associated diseases. Secondary Raynaud's, also called Raynaud's phenomenon, is caused by another disease usually an auto- immune disorder such as lupus, scleroderma, or rheumatoid arthritis. The cause of primary Raynaud's is not known but it is more common in women and in people from cold climates.