Definition of Phenomenon, Raynaud's
Phenomenon, Raynaud's: A condition resulting in discoloration of fingers and/or toes when a person is exposed to changes in temperature (cold or hot) or emotional events.
The skin discoloration occurs because an abnormal spasm of the of Raynaud's phenomenon.
Raynaud's phenomenon occurs with a number of conditions including rheumatic diseases (scleroderma, rheumatoid arthritis, systemic lupus erythematosus), hormone imbalance (hypothyroidism and carcinoid), trauma (frostbite, vibrating tools), medications (propranolol/INDERAL, estrogens, nicotine, bleomycin) and, rarely, cancer.
The phenomenon is named for the French physician Maurice Raynaud (1834-1881).Source: MedTerms™ Medical Dictionary
Last Editorial Review: 8/28/2013