Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
The two types of veins in the extremities are called superficial and deep. A blood clot in the deep veins is a concern because it can be dangerous.
A blood clot (thrombus) in the deep venous system of the leg becomes dangerous
when a piece of the blood clot breaks off (embolus, plural = emboli), travels
downstream through the heart into the pulmonary circulation system, and becomes
lodged in the lung.
A tendency to form blood clots can occur when people are
immobile, have blood tendency toward clotting, or have injury to veins or their
Symptoms of deep vein thrombosis include pain, swelling,
warmth, tenderness, and redness of the leg.
The diagnosis of DVT can be suggested by blood tests and confirmed by ultrasound or other imaging tests.
Treatment of DVT typically involves blood thinning medications (anticoagulants)
unless they cannot be used. In that situation, an inferior vena cava filter is
Arteries have thin muscles within their walls to be able to withstand
the pressure of the heart pumping blood to the far reaches of the body.
Veins don't have a significant muscle lining, and there is nothing pumping blood
back to the heart except physiology. Blood returns to the heart because
the body's large muscles squeeze the veins as they contract in their
normal activity of moving the body. The normal activities of moving the
body returns the blood back to the heart.
There are two types of veins in the leg; superficial veins and deep veins. Superficial veins lie just below the skin and are easily seen on the surface.
Deep veins, as their name implies, are located deep within the muscles of
the leg. Blood flows from the superficial veins into the deep venous system through
small perforator veins. Superficial and perforator veins have one-way valves
within them that allow blood to flow only in the direction of the heart when the
veins are squeezed.
A blood clot (thrombus) in the deep venous system of the leg is not dangerous in
itself. The situation becomes life-threatening when a piece of the blood clot breaks off
(embolus, pleural=emboli), travels downstream through the heart into the
pulmonary circulation system, and becomes lodged in the lung. Diagnosis and
treatment of a deep venous thrombosis (DVT) is meant to prevent pulmonary embolism.
Clots in the superficial veins do not pose a danger of causing pulmonary
emboli because the perforator vein valves act as a sieve to prevent clots from
entering the deep venous system. They are usually not at risk of causing pulmonary
Picture of how red blood cells and platelets form a blood clot
Reviewed by Melissa Conrad Stöppler, MD on 11/29/2013
Without muscle movement, blood stagnates and has a tendency to clot. In the deep veins of the legs and arms, no valve or filters block a straight shot to the heart and lungs if a clot should form and break off.
Deep venous thrombosis, or DVT, is the medical term for such a clot, and could be a harbinger of potential disaster.