What Is Raynaud's Disease?

Raynaud's disease and Raynaud's phenomenon are rare disorders that affect blood vessels. These disorders are marked by brief episodes of vasospasm (narrowing of the blood vessels). Vasospasm causes decreased blood flow to the fingers and toes, and rarely to the nose, ears, nipples, and lips. The fingers are the most commonly affected area, but the toes also are affected in 40 percent of people with Raynaud's.

When this disorder occurs without any known cause, it is called Raynaud's disease, or primary Raynaud's. When the condition occurs along with a likely cause, it is known as Raynaud's phenomenon, or secondary Raynaud's. Primary Raynaud's is more common and tends to be less severe than secondary Raynaud's.

When you have primary or secondary Raynaud's, cold temperatures or stressful emotions can trigger attacks. During these attacks, there is a brief lack of blood flow to the affected body part(s), and the skin can temporarily become white then bluish. As blood flow returns to the area, the skin turns red. The affected areas can throb or feel numb and tingly. With severe Raynaud's, prolonged or repeated episodes can cause sores or tissue death (gangrene).

Figure A shows the normal digital arteries with normal blood flow to the fingers. The inset images show cross-sections of a normal artery. Figure B shows white discoloration of the fingertips caused by blocked blood flow. Figure C shows narrowed digital arteries, causing blocked blood flow and purple discoloration of the fingertips. The inset images show cross-sections of a narrowed artery blocking the flow of blood.

It is normal for the body to keep its vital inner organs warm by limiting blood flow to the arms, legs, fingers, and toes. The body naturally does this in response to a long period of cold. This response can cause frostbite. In people with Raynaud's, the response to cold is quicker and stronger. The response can be triggered by mild or short-lived changes in temperature, such as:

• Taking something out of the freezer
• Temperatures that dip below 60 degrees Fahrenheit

In people with Raynaud's, blood flow is more strongly reduced in response to cold temperatures than in people without the disorder. When Raynaud's is severe (which is uncommon), exposure to cold for as little as 20 minutes can cause major tissue damage.

The blood vessels of people with Raynaud's also physically overreact to stressful emotions. It is normal during times of psychological stress for the body to release hormones that narrow its blood vessels. But for people with Raynaud's, this squeezing of blood vessels is stronger. This results in less blood reaching fingers, toes, and sometimes other extremities.

Outlook

For most people, primary Raynaud's is more of a bother than a serious illness and it can usually be managed with minor lifestyle changes. Secondary Raynaud's can be more difficult to manage, but several treatments may help prevent or relieve symptoms. Among the most important treatments for secondary Raynaud's is treating of the underlying condition.

June 2006