Although there are deep veins in both the legs and the arms blood clots more commonly occur in the legs.
Risk factors for deep vein thrombosis include prolonged immobility (such as long car rides or plane travel), traumatic injury (example; surgical intervention), and a variety of hematologic conditions that result in a propensity towards clot formation. Some of the hematologic conditions that increase the risk of blood clot are genetic in nature and can be evaluated with genetic testing.
When blood clot forms within a deep vein the vein can become partially or completely “clogged”. This obstruction to venous blood flow can result in increased pressure within tributary veins that are trying to flow into this pipe. In turn, this increased pressure within the more peripheral veins results in leakage of fluid from the veins into the tissues under the skin and can manifest as leg swelling.
Leg swelling is the most common symptoms of deep vein thrombosis. In addition to leg swelling, many patients report pain, aching discomfort, or tenderness in the area where the blood clot is formed. This pain and tenderness are likely related to inflammation in and around the vein wall as the body mounts a response to try and clear the blood clot.
Occasionally blood clot(s) in the deep veins in the legs can fragment and travel to the heart and lungs. This condition is known as pulmonary embolism. Common symptoms of pulmonary embolism include chest pain and shortness of breath. Occasionally patients with pulmonary embolism will report that they have been coughing up small amounts of blood.
The most common diagnostic test used to confirm or exclude the presence of blood clot(s) is ultrasound testing. Modern ultrasound machines can not only detect the presence of blood clot within a vein but can also accurately evaluate the flow of blood through (and around) the area of the blood clot.
The management of blood clot in the deep veins is guided by a patient’s clinical presentation, physical examination findings, and ultrasound findings.
In the majority of cases, patients with fresh blood clots in the legs are treated by using blood thinner medications for a variable period of time. The purpose of blood-thinning medications is to prevent extension of the blood clot into adjacent veins, prevent additional blood clots from forming, and allow the body to start the healing process.
In cases of extensive fresh blood clot patients may be a candidate for procedures designed to more aggressively bust-up (dissolve) the blood clot. The medical name for these procedures is pharmaco-mechanical thrombolysis (or venous thrombolysis). These procedures typically involve the temporary insertion of a thin piece of tubing into the vein that allows the strong clot-busting medication to be slowly trickled into the vein. There are several devices that can be used augment this clot-busting process.