Raynaud’s Phenomenon

What is Raynaud’s Phenomenon?

Raynaud’s phenomenon is a condition where the blood vessels in fingers and toes (and occasionally other areas) constrict upon exposure to cold, causing discoloration of the digits.

Disease vs. syndrome

There are 2 types of Raynaud’s phenomenon: primary Raynaud’s phenomenon or Raynaud’s disease, where symptoms are not associated with another disease, and secondary Raynaud’s phenomenon, or Raynaud’s syndrome, where symptoms are connected to another disease. Primary Raynaud’s phenomenon is not uncommon in young women.

  • Raynaud’s disease:
    • idiopathic. The cause is unknown
    • more common in young women
    • usually milder
  • Raynaud’s syndrome:
    • secondary to another disease
      • connective tissue diseases- systemic lupus erythematosus (SLE), scleroderma, rheumatoid arthritis, Sjogren’s syndrome, mixed connective tissue disease, etc.
      • Medications- beta-blockers, Bromocriptine, sulfasalazine, cyclosporine, some chemotherapies, others
      • Cryoglobulinemia
    • often more severe and may be more difficult to treat

What happens in Raynaud’s phenomenon:

The small blood vessels in the skin normally play a role in controlling the body’s temperature. They do this by constricting when it’s cold and reducing blood flow to the skin, therefore minimizing the loss of heat through the skin. They also dilate when it’s hot which increases the blood flow to the skin and helps lose some of the body heat. The blood vessels’ constriction and dilation is regulated by the sympathetic nervous system. Changes in the temperatures causes the sympathetic nervous system to fire signals to the blood vessels and direct them to either constrict or dilate. Interestingly, emotional stress can also cause a similar triggering of the sympathetic nervous system; which explains why people may have cold or sweaty hands when they are stressed.

In people with Raynaud’s phenomenon, the vessels have an abnormally exaggerated response to the sympathetic nervous system’s signals from cold weather.


Although Raynaud’s phenomenon most commonly affects the blood vessels supplying the fingers, it can also involve the feet as well as the ears, nose, face, and rarely, other areas. The classic Raynaud’s phenomenon attack resembles the colors of the United States flag: white, red, and blue. Initially, when the blood vessels constrict, the fingers may turn white from the lack of blood flow. The attack may involve one or more fingers and may happen in one or both hands
simultaneously. The most commonly involved fingers are index, middle and ring fingers. The white discoloration sometimes does not involve the entire finger, and one may see a distinct border between the areas of white and pink in the same finger. If the constriction is severe or prolonged and the oxygen supply in the blood is running low, the digit may turn blue/purple. When the fingers are warmed up and the vessels dilate again, the fingers may become red, indicating a rush of blood flow to the skin.

  • white: decreased blood flow
  • blue: lack of oxygen
  • red: blood flow re-established

During an attack of Raynaud’s phenomenon, the fingers or toes usually feel cold and they may be painful or numb. If the attacks are severe and prolonged, lack of blood supply to the area can eventually lead to death of the tissue (ulcers, necrosis, and gangrene). In severe cases, usually in people with Raynaud’s syndrome, tissue injury may be irreversible leading to loss of the finger or toe.

Diagnosing Raynaud’s phenomenon

Raynaud’s phenomenon is diagnosed clinically, based on one’s description of the fingers’ color change upon exposure to cold. When I evaluate someone for Raynaud’s phenomenon, my primary goal is to determine if the disease is primary or secondary. Primary Raynaud’s tends to be milder and responds better to conservative treatments. Secondary Raynaud’s (or Raynaud’s syndrome) can be more severe and more difficult to control. In addition, it can have implications depending on the disease it is associated with. For example, Raynaud’s symptoms associated with scleroderma can be associated with pulmonary hypertension, a very serious lung disease.

Blood tests are done in evaluation of Raynaud’s to rule out possible secondary diseases (see above). A rheumatologist may also do a nailfold capillary test, which involves looking closely at the small blood vessels around the nails. Normal blood vessels are thin and straight, but in severe Raynaud’s then can get inflamed, dilated, and tortuous. Recent studies have shown a correlation between abnormal nailfold blood vessels and development of pulmonary hypertension in people with scleroderma.

Treatment of Raynaud’s phenomenon

In milder cases, simple lifestyle changes may be all that one needs to control the disease. The more severe cases are treated with medications to prevent necrosis of digits and gangrene.

Keep fingers and toes warm

This may mean wearing socks more often and carrying a pair of gloves in your purse and using gloves to reach into a cold freezer. Keeping the entire body warm will also help warm the extremities- jackets, hats, scarfs. Running warm (but not hot) water over the affected fingers.

Stop smoking

Nicotine causes the blood vessels to constrict therefore worsening Raynaud’s.

Beware of medication reactions

Some medications can cause blood vessels to constrict. Some of these medications include beta-blockers (that lower blood pressure), pseudoephedrine (decongestants), among others.

Medical treatment

These are usually used in more persistent cases of Raynaud’s phenomenon. These medications work by dilating the blood vessel, helping restore blood to the extremities.

  • Calcium channel blockers– ex. Amlodipine, Nifedipine, Diltiazem
  • Topical nitroglycerine– ex. Nitrobid, Nitropaste
  • Other blood pressure medications– ex. Prazosin, Losartan
  • Phosphadiesterase inhibitors– ex. Sildenafil (Viagra), Pentoxyfylline (Trental), Cilostazole
  • Prostaglandins– ex.Prostacyclin


Procedural/Surgical treatment

In severe cases that are refractory to medications, surgical procedures are used to minimize injury.

  • Sympathectomy– cutting the nerves of the sympathetic nervous system that supply the blood vessels of the fingertips can their constriction
  • Amputation– If the damage is not reversible and not responsive to treatment, surgical amputation may be necessary.


Alternative treatments

Some nutritional supplements and herbs may help control milder cases of Raynaud’s phenomenon.

  • Ginko biloba
  • Fish oil
  • Vitamin D
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