Thrombophilia

Thrombophilia is a term to describe an inherited tendency to develop blood clots, which is known as venous thromboembolism (VTE). These episodes of VTE tend to occur at a young age (prior to 40 years), may occur in the absence of a known cause and often recur. Between 2.5-5% of the population will suffer from a thrombosis or clotting episode during their lives. These events are often associated with another risk factor such as surgery, illness, immobility or bed rest, pregnancy, and birth control or hormone therapy. These inherited tendencies lead to an increased risk of clotting problems throughout an affected individual’s life. Identifying an individual’s underlying clotting disorder is a high priory in planning his/her care. A detailed review of personal and family history by the patient’s medical care provider is important and may reveal a family history of thrombosis.

Symptoms

A thrombosis or clot occurs when the natural clotting system is not working correctly and a clot continues to grow within a blood vessel. Clots are made of platelets (the blood component that initiates clotting at an injury site) and fibrin (a tough meshwork the body produces from clotting factors) and are formed in arteries or veins. Arteries are the vessels that deliver oxygenated blood from the heart to the tissues and organs; veins are the vessels that return blood to the heart for re-oxygenation to the lungs. Arteries are stiffer and usually larger vessels compared to veins, which tend to be thinner and smaller. The blood flow in arteries is very fast. Blockage in any of these blood vessels by a clot can lead to decreased blood flow to an area (ischemia), tissue death (necrosis) and damage to an organ, such as with heart attacks (myocardial infarcts) or stroke (cerebral infarcts). Other symptoms may include pain with activity such as walking (claudication), continuous pain, pallor (loss of normal tissue color) or numbness or tingling (parasthesia). Blood flow in the venous system is much slower, as it is a low-pressure system. Therefore, most clots occur in the veins.

DVT

Most venous clots occur in the calf veins and are called a deep vein thrombosis or DVT. A DVT causes pain, redness and swelling of the affected extremity. Often the clot causes the small blood vessels around the obstructed vessel to become larger to accommodate the increased blood and pressure. These enlarged veins may become visible under the surface of the skin.

Embolus

An embolus is one of the major complications of a DVT. A thrombus (often from the leg) can break off from the main clot and travel through the blood vessels into the lung. This is called a pulmonary embolus (PE). A pulmonary embolus most often occurs with blood clots that have formed in the calf veins. Symptoms of PE include shortness of breath, chest pain, feeling anxious, cough, coughing up blood, sweating and dizziness. Not all of these symptoms occur with every PE. Pulmonary embolus is an under-recognized and under-diagnosed problem, especially in younger patients who are not in the hospital. PE may be misdiagnosed as pleurisy, pneumonia or a variety of other conditions. A life-threatening PE can be greatly reduced by early treatment of a DVT with blood thinners.

The diagnosis and treatment of thrombophilia is a subspecialty of hematology. A growing number of hemophilia treatment centers (HTCs) are providing comprehensive healthcare services to this special patient population. For more information on thrombophilia, contact your local HTC.