Raynaud’s phenomenon is a condition in which cold temperatures or strong emotions cause blood vessel spasms. This blocks blood flow to the fingers, toes, ears, and nose. Raynaud’s phenomenon can be linked to other conditions. This is called secondary Raynaud’s phenomenon. Most people with the condition are over age 30. Common causes are:, diseases of the arteries (such as atherosclerosis and Buerger’s disease), drugs that cause narrowing of arteries (such as amphetamines, certain types of beta-blockers, some cancer drugs, certain drugs used for migraine headaches), arthritis and autoimmune conditions (such as scleroderma, Sjogren’s syndrome, rheumatoid arthritis, and systemic lupus erythematosus) , repeated injury or usage (such as from typing, playing the piano, or heavy use of hand tools), smoking, frostbite, and thoracic outlet syndrome. Raynaud’s phenomenon can also occur without another cause. This is called primary Raynaud’s phenomenon. It most often begins in people younger than age 30.