Definition
When a vein is inflamed (phlebitis) it often forms a blood clot (thrombus), which restricts blood flow through the vein. This condition is known as venous thrombosis.
Generally two types of clots form in veins:
- A superficial vein, or varicose vein, can become inflamed and clot beneath the surface of the skin. This can be painful, but is not life-threatening.
- A deep, interior vein can also develop a clot. This is potentially a more serious condition. A portion of the clot can break away and travel through the veins to the lungs. Blockage of a large vessel in the lungs may cause serious complications and possibly death.
Causes
Figure 1. A. Normal Vein and Valve
and B. Vein with Blood Clot
Clots most commonly occur when the innermost layer of a blood vessel is damaged by infection, surgery, or a previous thrombosis. If damage occurs, blood clots can develop when the same clotting factors that stop external bleeding begin to function inappropriately in deep veins. The clot will form in a vein valve cup, and may grow large enough to block the vein, or become dislodged and travel to the lungs (Fig. 1B).
If the blockage is not treated, it can jeopardize an affected limb by obstructing blood flow. This causes leg swelling and can lead to chronic venous insufficiency (CVI).
Less common causes of thrombosis are:
- Lengthy periods of immobility (such as sitting on an airplane or confinement to bed or wheelchair). These can disrupt the balance of blood pressure in the veins, slow circulation and impair blood flow.
- Clotting abnormalities associated with cancer, sickle-cell anemia, estrogen or progestin replacement therapy, dehydration and thickening of the blood.
Warning Signs
The symptoms of venous thrombosis are:
- Sudden, continuous deep pain in the calf or thigh
- Deep pain in a leg which increases, either when exercising or from standing for long periods
- Frequent redness and swelling
- Warm skin
- Leg fatigue
- Surface veins become more visible
Treatment & Prevention
Thrombosis in varicose or superficial veins is normally treated with anti-inflammatory drugs, together with elevating the legs to reduce pressure.
Deep vein thrombosis is immediately treated with anticoagulants (blood thinners), together with bed rest and elevation of the legs above heart level to reduce pressure and promote the flow of blood back to the heart. If blood thinners are used for long-term treatment, patients are cautioned not to take certain other medications, especially aspirin, which may interact with them.
When a patient resumes walking, elastic compression of the lower leg controls swelling, collapses the superficial veins and increases blood flow in the deep veins to promote healing. If there is an associated venous ulcer of the ankle, this same treatment promotes healing.
People who are vulnerable to blood clots should not smoke, because tobacco promotes clot formation.
What is VascularCures doing about it?
VascularCures is supporting the research of Rajabrata Sarkar, MD, PhD, who is working to understand how blood clots cause scarring in veins and to develop new treatments to prevent it. He is also unraveling the genetic mechanism that helps in the growth of new arteries. Find out more...
Where can I find out more?
Dr. Rajabrata Sarkar answers patients' questions about blood clots (deep vein thrombosis. Click here to learn more.
