Raynaud's phenomenon is a condition that affects blood vessels, primarily in the fingers and toes. It is characterized by episodes during which blood vessels in the digits narrow in response to cold temperatures or on occasion to emotional stress. Most people with Raynaud's phenomenon have the primary form (also known as Raynaud's disease), which is not associated with any underlying disease. When Raynaud's phenomenon is caused by or associated with an underlying disease, it is referred to as secondary Raynaud's phenomenon. The most common cause of secondary Raynaud's phenomenon is connective tissue disease, such as scleroderma and lupus.

White, blue, and red. Raynaud's phenomenon classically presents with color changes in the digits. During the initial phase, the skin of the digits turns white as a result of narrowing of the blood vessels. This is usually followed by numbness and the sensation of cold and sometimes a bluish discoloration of the skin. Once the circulation begins to return the affected digits may turn red and throb prior to returning back to normal. Attacks often begin in one finger or toe and move on to other fingers or toes. Sometimes only one or two fingers or toes are affected. Different areas may be affected at different times. Raynaud's episodes can be fairly brief, lasting only minutes, to continuing for as long as hours.

Who gets Raynaud's? In general, Raynaud's is more common in people living in colder climates. Primary Raynaud's is far more common in women than in men. Usually it develops before the age of 30, and often there are other family members with the condition. Secondary Raynauds's begins more commonly after the age of 30. In addition to being associated with connective tissue diseases, it is also seen more commonly in people who have sustained injuries to the hands and feet, smokers, and workers performing repetitive tasks or using vibrating tools. Individuals taking certain medications, such as migraine or blood pressure medications, can also be affected by Raynaud's.

How is Raynaud's diagnosed? There is no single blood test available to diagnose Raynaud's phenomenon. The characteristic color changes and precipitating factors often provides enough information for a doctor to make the diagnosis. Simple office tests (nailfold capillaroscopy and the cold stimulation test) are occasionally performed to confirm that the patient is experiencing Raynaud's. Distinguishing the primary from the secondary form, however, may be more difficult. Questioning about possible secondary factors---injuries, occupation, medications, etc.---may provide the underlying cause. In cases where connective tissue disease is suspected tests such as the antinuclear antibody (ANA) a erythrocyte sedimentation rate (ESR or "sed rate") may be performed.

How is Raynaud's treated? Primary Raynaud's (Raynaud's disease) has no cure. Fortunately, for the most part, symptoms are mild and not associated with any blood vessel or tissue damage. When treatment is necessary, most people who have primary Raynaud's can manage the condition with lifestyle changes including:

Some people with Raynaud's, particularly those with a secondary cause, can develop serious complications, such as ulcerations on fingers or toes. In addition to lifestyle measures, these individuals may require treatment with medications. Medications that dilate blood vessels, such as calcium channel blockers (nifedipine, diltiazem or amlodipine) are considered to be the first line treatment when medications are necessary. Another class of high blood pressure medications, alpha receptor blockers prazosin (Minipres) or doxazosin (Cardura) help in some cases. Other medications that may offer benefit include low dose aspirin and the blood-pressure medications losartan (Cozaar) and prazosin (Minipress, Cardura).

What's on the horizon? Research is being conducted into more effective diagnostic measures, such as the use of laser Doppler imaging, as well as into new treatments to improve blood flow for those who have Raynaud's phenomenon.