Raynaud's phenomenon is a disorder that affects the blood vessels in the fingers, toes, ears, and nose. Although estimates vary, recent surveys show that Raynaud's phenomenon may affect 5 to 10 percent of the general population in the United States.
Women are more likely than men to have the disorder.
Raynaud's phenomenon appears to be more common in people who live in colder climates. However, people with the disorder who live in milder climates may have more attacks during periods of colder weather. For most people, an attack is usually triggered by exposure to cold or emotional stress. In general, attacks affect the fingers or toes but may affect the nose, lips, or ear lobes. To maintain this temperature, the blood vessels that control blood flow to the skin surface move blood from arteries near the surface to veins deeper in the body.