Raynaud phenomenon

A transient peripheral vasospastic disorder characterized by episodic digital ischemia triggered by cold exposure or emotional stress, leading to well-demarcated triphasic (white-blue-red) color changes of the fingers and/or toes, with associated numbness or pain. The cause of primary Raynaud is unknown, but linked to genetics, sex, age, and cold climates. Secondary Raynaud is caused by autoimmune diseases (scleroderma, lupus, rheumatoid arthritis, Sjögren's syndrome), atherosclerosis, occupational injury (vibrating tools/machinery), medications (β-blockers, migraine drugs, amphetamines), and enviromental factors (smoking, frostbite, carpal tunnel syndrome).