What is Raynaud's phenomenon?
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 (tighten or
close). Raynaud's phenomenon can occur on its own, or it can occur
with another condition such as scleroderma or lupus.
Although estimates vary, recent surveys show that Raynaud's
phenomenon might affect 5 percent to 10 percent of the general
population in the United States. Women are more likely than men to
have the disorder. An attack of Raynaud's is usually
triggered by exposure to cold or emotional stress. Along with the
fingers and toes, the nose, lips, or ear lobes can also be
affected.
Under normal circumstances, when a person is exposed to cold,
his or her body's response is to slow the loss of heat. The body
does this by causing the blood vessels that control the blood flow
to the skin's surface to move blood from the surface arteries
to vessels deeper in the body.
For people who have Raynaud's, however, this normal body
response is intensified by contractions of the small blood vessels
that supply blood to the fingers and toes. In some cases, this
causes the arteries of the fingers and toes to collapse. The result
is a greatly decreased supply of blood to the affected body areas,
causing skin discoloration.
A person with Raynaud's phenomenon can experience three
phases of skin color changes. Pallor (whiteness) might occur in
response to the collapse of the arteries in an affected body part.
Cyanosis (blueness) appears because the fingers or toes are not
getting enough oxygen-rich blood. Other symptoms that occur during
cyanosis are feeling cold and numbness. Rubor (redness) occurs as
the blood returns to the affected areas. After an attack is over,
throbbing and tingling might occur in the fingers and toes. Attacks
of Raynaud's phenomenon can last from less than a minute to
several hours.
Doctors classify Raynaud's phenomenon as either primary or
secondary.
Primary Raynaud's phenomenon -- Also known as
Raynaud's disease, this form is the more common and the
milder of the two types. A person who has primary Raynaud's has no
other diseases that might cause Raynaud's symptoms or
associated medical problems. About 75 percent of all cases of
primary Raynaud's phenomenon are diagnosed in women between
ages 15 and 40. People with the primary form rarely develop other
diseases related with Raynaud's such as lupus or
scleroderma.