Definition of Raynaud's phenomenon:

Raynaudâ ' s phenomenon is a condition in which cold temperatures or strong emotions cause blood vessel spasms that block blood flow to the fingers, toes, ears, and nose.

Causes, incidence, and risk factors:

Raynaud's phenomenon can be associated with diseases of the arteries such as:

• Atherosclerosis
• Buerger's disease
• Rheumatoid arthritis
• Scleroderma
• Systemic lupus erythematosus

Other causes of Raynaud's phenomenon may include:

• Repeated injury, particularly from vibrations such as those caused by typing or playing the piano
• Overdose of of certain medicines, including ergot compounds and methysergide
• Smoking