What Causes Capillaries to Dilate?

causes-capillaries-dilate Credit: Science Photo Library - STEVE GSCHMEISSNER/Brand X Pictures/Getty Images

Dilated capillaries are caused by a variety of factors, including radiation, sun damage, pregnancy, unbalanced estrogen levels and rosacea, according to Care Fair. They may also be caused by prescription medications or autoimmune diseases. Lifestyle factors like heavy drinking, smoking, or harsh scrubbing of the face can also cause dilated capillaries. Occasionally, dilated capillaries may appear in skin without medical problems due to heredity or the natural aging process, according to Dr. David Green.

Dilated capillaries are also known as broken capillaries, broken blood vessels or broken veins. The term "broken" is misleading, according to Dr. Patricia Wong, medical and aesthetic dermatologist in Palo Alto, Calif. The capillaries are not actually broken, but inflamed. They are tiny veins which cluster together near the surface of the skin, causing a red, pink or purple bruise-like area. The skin takes on a chronically flushed look, especially during periods of heavy exertion or hot weather. Dilated capillaries most often appear on the face, especially around the nose and mouth, but may also appear on the legs.

While dilated capillaries are generally considered harmless, they do pose a cosmetic concern for those who suffer from them. According to Care Fair, many treatment options exist to remove dilated capillaries or diminish their appearance; these options include electrolysis, laser surgery and cosmetic surgery. Any treatments must be performed by a dermatologist or highly trained esthetician.