DID YOU KNOW...
By Tara McDougall & Alicia Walczak
Have you ever sustained an injury to your leg and gone to the doctor only to be told that you have nothing to worry about? Have you ever spent several hours traveling without standing up and moving around? Have you ever been ordered on bed rest by a doctor but not told of the danger of staying in bed for more then a few days without exercising your legs? Do you have atherosclerosis or a blood disorder? These are all risk factors for developing a deep vein thrombosis (DVT).
To understand what a blood clot (also known as a thrombus) is and how it works, it is important to first understand what blood is. There are four major components to blood:
Each component of blood and the vessels through which it flows, helps ensure that oxygen rich blood reaches our tissues via the arteries and oxygen poor blood is taken back to the lungs via the veins to become reoxygenated. When there is an interruption in blood flow such as an injury, each of the components work together to help repair the injury and stop blood loss.
Platelets, or thrombocytes, are responsible for stopping blood loss through vascular (blood vessel) damage/injury. The formation of a platelet plug, more commonly known as a scab, stops blood from leaving the site of an injury. A thrombus is a blood clot that is formed at the site of injury. Sometimes thrombi form without the provocation of injury around valves in the deep veins of the leg, hence the term, deep vein thrombosis.
Pulmonary embolism is a condition closely related to DVT. A pulmonary embolism occurs when a piece of the blood clot breaks away from the thrombus and travels to the pulmonary arteries thereby blocking blood flow to the lungs. It is not known why a blood clot dissolves for some people and for others it travels to the lungs. However, DVT is a potentially life threatening situation.
More than half of people with pulmonary embolisms do not have symptoms.
Who is at risk for developing DVT?
Over 150 years ago, a prominent German Doctor, Roudolph Virchow, surmised that thrombus formation and propagation stemmed from abnormalities in three vascular areas, now known as Virchow's Triad. The three main components of Virchow’s Triad, and how they relate to DVT, are:
Injury to the endothelium (the lining of arteries) such as caused by smoking, initiates a process by which a fatty plaque (atheroma) accumulates in the injured area and thus reduces blood flow. Subsequent studies determined that in the case of hyper-cholesterolemia, fat-laden particles can infiltrate the vessel walls in the absence of injury to the endothelium.
Signs and Symptoms
See a doctor right away if you experience any of the following symptoms because you may have a deep vein thrombosis or a complication from a DVT known as a pulmonary embolism:
Questions to ask your doctor if you think you might have a blood clot
How is it diagnosed?
Your doctor will acquire your medical history, perform a physical, run a series of tests, and identify possible risk factors you may have. Medical history includes your current state of health, any prescriptions you are taking, recent surgeries or injuries, and if you have cancer. A physical examination will include your doctor checking your leg for signs of a blood clot, checking that your blood pressure is in the normal range, and if your heart and lungs are functioning normally. Your doctor willalso run a series of tests to help detect if you have a blood clot. These tests include an ultrasound, which is the most common, a D-dimer test or a venography. Your doctor also may order an MRI or a CAT scan.
The main goal of treatment is to stop the clot from growing or having it move into the lungs. Both are very serious. Another goal is to reduce the chance of reoccurrence. The following are treatments that one can expect:
Anticoagulants: decrease the body’s ability to clot
Other treatments include a vena cava filter or compression stockings
The articles, on the Cardiac Health Foundation of Canada website, are presented with the understanding that the Foundation is providing information only and not rendering medical advise. Please check with your family physician, specialist or health care professional before implementing any of the ideas expressed in these articles.