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Harvard Medical School

Raynaud's Phenomenon

What Is It?

When healthy people are in a cold environment, the tiny blood vessels in their skin constrict, or narrow, in an effort to conserve heat. In people with Raynaud's phenomenon (also called Raynaud's disease or Raynaud's syndrome), that natural response to cold is extreme. The tiny blood vessels go into spasm, narrowing and reducing the blood flow to the affected areas. This response, called vasospasm, is seen most often in the fingers and toes, but it also can occur in the ears, cheeks and nose. In some people with the disorder, the constriction also can occur in response to emotional stress or a rapid change of temperature from warm to cool.

The effect of this can be dramatic and frightening, but it is temporary and rarely dangerous. The color of the affected skin is very different from the color of normal skin. The affected area may be numb or tingling ("pins and needles"). Once the affected area is warmed, the blood vessels relax and expand, which allows more blood flow. The skin then turns pink or red as the blood returns, and there may be a feeling of warmth, throbbing or soreness.

Approximately 5% to 10% of people have Raynaud's phenomenon, and women are more likely to develop the disorder than men. No one knows what causes Raynaud's phenomenon. People who do not have any other symptoms or disease are said to have primary Raynaud's. People who have Raynaud's phenomenon as part of another disease or condition are said to have secondary Raynaud's.

Secondary Raynaud's phenomenon commonly is linked to connective-tissue disorders, such as scleroderma and lupus. It also can occur as a result of damage to blood vessels from injury, frostbite or use of jarring machinery, such as jackhammers or chainsaws. Smoking, some heart and migraine medications and diseases that affect circulation (such as atherosclerosis) also can cause secondary Raynaud's or can worsen pre-existing Raynaud's phenomenon.