A Guide to Raynaud's Phenomenon

Raynaud's Phenomenon Explained

Raynaud's phenomenon is a disorder that affects the blood vessels in the fingers, toes, ears, and nose. This disorder is characterized by episodic attacks, called vasospastic attacks, that cause the blood vessels in the digits (fingers and toes) to constrict (narrow). Raynaud's phenomenon can occur on its own, or it can be secondary to other conditions.

Although estimates vary, recent surveys show that Raynaud's phenomenon may affect 5 to 10 percent of the general population in the United States. Women are more likely than men to have the disorder. Raynaud's phenomenon appears to be more common in people who live in colder climates. However, people with the disorder who live in milder climates may have more attacks during periods of colder weather.

What Happens During an Attack?

For most people, an attack is usually triggered by exposure to cold or emotional stress. In general, attacks affect the fingers or toes but may affect the nose, lips, or ear lobes.

Reduced Blood Supply to the Extremities

When a person is exposed to cold, the body's normal response is to slow the loss of heat and preserve its core temperature. To maintain this temperature, the blood vessels that control blood flow to the skin surface move blood from arteries near the surface to veins deeper in the body.

For people who have Raynaud's phenomenon, this normal body response is intensified by the sudden spasmodic contractions of the small blood vessels that supply blood to the fingers and toes. The arteries of the fingers and toes may also collapse. As a result, the blood supply to the extremities is greatly decreased, causing a reaction that includes skin discoloration and other changes.

Changes in Skin Color and Sensation

Once the attack begins, a person may experience three phases of skin color changes (white, blue, and red) in the fingers or toes. The order of the changes of color is not the same for all people, and not everyone has all three colors.

  • Pallor (whiteness) may occur in response to spasm of the arterioles and the resulting collapse of the digital arteries.
  • Cyanosis (blueness) may appear because the fingers or toes are not getting enough oxygen-rich blood.

The fingers or toes may also feel cold and numb. Finally, as the arterioles dilate and blood returns to the digits, redness may occur. As the attack ends, throbbing and tingling may occur in the fingers and toes. An attack can last from less than a minute to several hours.

How Is Raynaud's Phenomenon Classified?

Doctors classify Raynaud's phenomenon as either the primary or the secondary form. In medical literature, "primary Raynaud's phenomenon" may also be called:

  • Raynaud's disease
  • idiopathic Raynaud's phenomenon
  • primary Raynaud's syndrome

The terms idiopathic and primary both mean that the cause is unknown.

Primary Raynaud's Phenomenon

Most people who have Raynaud's phenomenon have the primary form (the milder version). A person who has primary Raynaud's phenomenon has no underlying disease or associated medical problems. More women than men are affected, and approximately 75% of all cases are diagnosed in women who are between 15 and 40 years old.

Research shows that less than 10% of people who have only vasospastic attacks for several years, without involvement of other body systems or organs, rarely have or will develop a secondary disease later.

Secondary Raynaud's Phenomenon

Although secondary Raynaud's phenomenon is less common than the primary form, it is often a more complex and serious disorder. Secondary means that patients have an underlying disease or condition that causes Raynaud's phenomenon. Connective tissue diseases are the most common cause of secondary Raynaud's phenomenon. Some of these diseases reduce blood flow to the digits by causing blood vessel walls to thicken and the vessels to constrict too easily. Raynaud's phenomenon is seen in patients with:

Raynaud's phenomenon also can occur in patients who have other connective tissue diseases, including:

Possible causes of secondary Raynaud's phenomenon, other than connective tissue diseases, are:

  • carpal tunnel syndrome
  • obstructive arterial disease
  • some drugs (such as beta-blockers, ergotamine preparations, certain chemotherapy agents)
  • drugs that cause vasoconstriction (such as some over-the-counter cold medications and narcotics)
  • people in certain occupations (such as workers exposed to vinyl chloride or workers who operate vibrating tools)

People with secondary Raynaud's phenomenon often experience associated medical problems. The more serious problems are skin ulcers or gangrene in the fingers or toes. Painful ulcers and gangrene are fairly common and can be difficult to treat. Weakness in the muscle of the esophagus may cause heartburn or difficulty in swallowing.

If a doctor suspects Raynaud's phenomenon, he or she will ask the patient for a detailed medical history. The doctor will then examine the patient to rule out other medical problems. The patient might have a vasospastic attack during the office visit, which makes it easier for the doctor to diagnose Raynaud's phenomenon. Most doctors find it fairly easy to diagnose Raynaud's phenomenon but more difficult to identify the form of the disorder.

Diagnostic Criteria for Raynaud's Phenomenon

Doctors use certain diagnostic criteria to diagnose primary or secondary Raynaud's phenomenon.

Criteria: Primary Raynaud's Phenomenon

The diagnostic criteria used to diagnose primary raynaud's phenomenon include:

  • Periodic vasospastic attacks of pallor (whiteness) or cyanosis (blueness) (Note: some doctors include the additional criterion of the presence of these attacks for at least 2 years)
  • Normal nailfold capillary pattern
  • Negative antinuclear antibody test (ANA)
  • Normal erythrocyte sedimentation rate (ESR)
  • Absence of pitting scars or ulcers of the skin, or gangrene (tissue death) in the fingers or toes

Criteria: Secondary Raynaud's Phenomenon

The diagnostic criteria used to diagnose secondary raynaud's phenomenon include:

  • Periodic vasospastic attacks of pallor (whiteness) and cyanosis (blueness)
  • Abnormal nailfold capillary pattern
  • Positive antinuclear antibody test (ANA)
  • Abnormal erythrocyte sedimentation rate (ESR)
  • Presence of pitting scars or ulcers of the skin, or gangrene in the fingers or toes

Diagnostic Tests for Raynaud's Phenomenon

Several diagnostic tests may be ordered by your doctor to help confirm a Raynaud's diagnosis.

Nailfold Capillaroscopy

Nailfold capillaroscopy (study of capillaries under a microscope) can help the doctor distinguish between primary and secondary Raynaud's phenomenon. During this test, the doctor puts a drop of oil on the patient's nailfolds, the skin at the base of the fingernail. The doctor then examines the nailfolds under a microscope to look for abnormalities of the tiny blood vessels called capillaries. If the capillaries are enlarged or deformed, the patient may have a connective tissue disease.

The doctor may also order two particular blood tests, an antinuclear antibody test (ANA) and an erythrocyte sedimentation rate (ESR).

Antinuclear Antibody Test (ANA)

The antinuclear antibody test (ANA) test determines whether the body is producing special proteins (antibodies) often found in people who have connective tissue diseases or other autoimmune disorders. Patients with these connective tissue diseases or other autoimmune disorders, make antibodies to the nucleus, or command center, of the body's cells. These antibodies are called antinuclear antibodies and are tested for by placing a patient's blood serum on a microscope slide containing cells with visible nuclei. A substance containing fluorescent dye is added which binds to the antibodies. Under a microscope the abnormal antibodies can be seen binding to the nuclei.

Erythrocyte Sedimentation Rate (ESR)

The erythrocyte sedimentation rate (ESR) is a diagnostic test for inflammation. The erythrocyte sedimentation rate (ESR) test is a measure of inflammation in the body and tests how fast red blood cells settle out of unclotted blood by measuring the rate at which the red blood cells fall to the bottom of a tube over time. An increased sedimentation rate corresponds to increased non-specific inflammation in the body. It is often called a "sedrate" for short.

Cold Stimulation Test

The cold stimulation test is another test that your doctor might use to diagnose Raynaud's phenomenon. A cold stimulation test measures the temperature of each finger after being submerged in an ice-water bath. Heat sensors are attached to your fingers and temperatures are recorded until your finger temperature measures the same as it was before being placed in the ice-water bath.

What Research Is Being Conducted To Help People Who Have Raynaud's Phenomenon?

Researchers are studying ways to better diagnose Raynaud's phenomenon and predict and monitor its course and association with other diseases. They are also evaluating the use of new drugs to improve blood flow in Raynaud's phenomenon. Researchers in scleroderma and other connective tissue diseases are also investigating Raynaud's phenomenon in relation to these diseases.

The aims of treatment are to reduce the number and severity of attacks and to prevent tissue damage and loss in the fingers and toes. Most doctors are conservative in treating patients with primary and secondary Raynaud's phenomenon; that is, they recommend non-drug treatments and self-help measures first.

Doctors may prescribe medications for some patients, usually those with secondary Raynaud's phenomenon. In addition, patients are treated for any underlying disease or condition that causes secondary Raynaud's phenomenon.

Non-Drug Treatments and Self-Help Measures

Several nondrug treatments and self-help measures can decrease the severity of Raynaud's attacks and promote overall well-being.

Take Action During an Attack:

An attack should not be ignored. Its length and severity can be lessened by a few simple actions. The first and most important action is to warm the hands or feet. In cold weather, people should go indoors. Running warm water over the fingers or toes or soaking them in a bowl of warm water will warm them. Taking time to relax will further help to end the attack. If a stressful situation triggers the attack, a person can help stop the attack by getting out of the stressful situation and relaxing. People who are trained in biofeedback can use this technique along with warming the hands or feet in water to help lessen the attack.

Keep Warm:

It is important not only to keep the extremities warm but also to avoid chilling any part of the body. In cold weather, people with Raynaud's phenomenon must pay particular attention to dressing.

  • Several layers of loose clothing, socks, hats, and gloves or mittens are recommended.
  • A hat is important because a great deal of body heat is lost through the scalp.
  • Feet should be kept dry and warm.
  • Some people find it helpful to wear mittens and socks to bed during winter.
  • Chemical warmers, such as small heating pouches that can be placed in pockets, mittens, boots, or shoes, can give added protection during long periods outdoors.

People with Raynaud's phenomenon should also be aware that air conditioning can trigger attacks. Turning down the air conditioning or wearing a sweater may help prevent attacks. Some people also find it helpful to use insulated drinking glasses and to put on gloves before handling frozen or refrigerated foods.

Quit Smoking:

The nicotine in cigarettes causes the skin temperature to drop, which may lead to an attack.

Control Stress:

Stress management is important. Stress and emotional upsets may trigger an attack, particularly for people who have primary Raynaud's phenomenon, learning to recognize and avoid stressful situations may help control the number of attacks. Many people have found that relaxation or biofeedback training can help decrease the number and severity of attacks. Biofeedback training teaches people to bring the temperature of their fingers under voluntary control.


Many doctors encourage patients who have Raynaud's phenomenon, particularly the primary form, to exercise regularly.

Most people find that exercise:

  • promotes overall well-being
  • increases energy level
  • helps control weight
  • promotes restful sleep

You should always talk to your doctor before starting an exercise program. People who have secondary Raynaud's phenomenon should also talk to their doctors before exercising outdoors in cold weather.

See Your Doctor:

People with Raynaud's phenomenon should see their doctors if they are worried or frightened about attacks or if they have questions about caring for themselves. They should always see their doctors if attacks occur only on one side of the body (one hand or one foot) and any time an attack results in sores or ulcers on the fingers or toes.

Treatment With Medications

People with secondary Raynaud's phenomenon are more likely than those with the primary form to be treated with medications.

Many doctors believe that the most effective and safest drugs are calcium-channel blockers, which relax smooth muscle and dilate the small blood vessels. These drugs decrease the frequency and severity of attacks in about 65% of patients who have primary and secondary Raynaud's phenomenon. These drugs also can help heal skin ulcers on the fingers or toes.

Other patients have found relief with drugs called alpha blockers that counteract the actions of norepinephrine, a hormone that constricts blood vessels. Some doctors prescribe a drug that relaxes blood vessels, such as nitroglycerine paste, which is applied to the fingers, to help heal skin ulcers. Often, patients with the secondary form will not respond as well to treatment as those with the primary form of the disorder.

Patients should keep in mind that the treatment for Raynaud's phenomenon is not always successful.

View Article Sources
  • NIH Publication No. 01-4911