Varicose Veins & Spider Veins
Medical Author: Siamak Nabili, MD, MPH
Medical Editor: Melissa Conrad Stöppler, MD
What are veins and what is their function?
Veins are blood vessels that return blood from all the organs in the body
toward the heart. When the different organs use oxygen from the blood to perform
their functions, they release the used blood containing waste products (such as
carbon dioxide) into the veins. Blood in the veins is then transported to the
heart and returned to the lungs, where the waste carbon dioxide is released and
more oxygen is loaded by the blood and taken back to the rest of the body by the
arteries.
Veins also act as a storage for unused blood. When the body is at rest, only
a portion of the available blood in the body circulates. The rest of the blood
remains inactive in the veins and enters the active circulation when the body
becomes more active and needs the additional blood to carry oxygen to entire
body. This storing capacity is due to the elasticity (flexibility to expand) of
the walls of the veins.
Veins have different sizes depending their location and their function. The
largest veins are in the center of the body; these collect the blood from all
the other smaller veins and channel it into the heart. The branches of these
large veins get smaller and smaller as they move away from the center of the
body. The veins closer to the skin surface are called superficial veins. The
veins that are deeper and closer to the center of the body are called deep
veins. There are also other veins that connect the superficial veins to the deep
ones which are called the perforating veins.
What are varicose veins and spider veins?
Veins can bulge with pools of blood when they fail to circulate the blood
properly. These visible and bulging veins, called varicose veins, are more
common in the legs and thighs, but can develop anywhere in the body.
Large varicose veins can be visible, bulging, palpable (can be felt by
touching), long, and dilated (greater than 4 millimeters in diameter).
Small
"spider veins" also can appear on the skin's surface. These may look like short,
fine lines, "starburst" clusters, or a web-like maze. They are typically not
palpable. Spider veins are most common in the thighs, ankles, and feet. They may
also appear on the face. The medical term for them spider veins is
telangiectasias.
Picture of Varicose Veins
Picture of Spider Veins
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