Blood clots in the large veins of the leg called Deep Vein Thrombosis (DVT) occur in hundreds of thousands of Americans each year. When blood clots in the lungs (called Pulmonary Embolus (PE)), are combined with DVT occurrence nearly one million Americans per year develop a blood clot condition know as Venous Thromboembolism (VTE). There were nearly 300,000 deaths in the US due to VTE in 2005. (1) Other studies estimate up to 2 million blood clot related conditions occur per year in the United States.
Of the nearly 300,000 fatalities, two thirds developed VTE in hospitals while one third developed VTE in the general community. The referenced article found that VTE occurrence and fatalities are substantially higher than previously estimated based on data provided by the American Society of Hematology.
While PE is considered separately, PE is often caused by DVT when portions or all of the clot move through the venous system to the lungs. Clot migration also is a cause of increased risk of heart attacks (myocardial infarction) and stroke. (2) Causes of DVT are immobility, faster that normal clotting blood and trauma to the veins.
The majority of VTE occurrences are in hospital settings because all three causes are likely following surgery or extended hospital stays. Immobility and trauma to veins in a hospital setting are most common while hypercoagulability (faster clotting blood) due to blood clotting time adjustments prior to surgery is less probable.
In the hospital, the patient is at the mercy of the hospital staff who’s awareness of VTE has been heightened by recent studies. With proper VTE preventative measures the ratio of hospital to community occurrence can be greatly reduced.
The general community can take steps to reduce DVT occurrence:
Immobility is generally avoidable. Walking and simple non-strenuous exercise of the calf muscles prevent pooling of the blood in the lower leg. While sitting you can exercise your calf muscles by sitting with the balls of your feet on the floor then lowering and raising your heels. This simple exercise alternately contracts and releases your calf muscles stimulating blood flow with the calf muscle pump. A surprisingly large number of DVT occurrences are due to immobility during long haul air travel. Activating your calf muscle pump by walking or working the calf muscle while sitting greatly reduces the chance of DVT. If you are in a high DVT risk group consult your physician before a long haul flight.
Hypercoagulability(faster than normal blood clotting) has a variety of causes and some require a physician’s assistance to detect and control. Women on birth control pills and especially women on birth control that also smoker are at higher risk of DVT. All smokers are at higher risk of developing clots. Annual physicals should include a Prothrombin (PT) blood test also known as a protime test to determine your blood clotting factor. The results of a PT test is normally expressed as an International Normalized Ratio (INR). An INR of 1 is normal with a general range from 0.8 to 1.2 the target range. INR can be controlled by diet and proper hydration. Diet wise, avoid vitamin supplements that contain vitamin K and limit consumption of foods high in vitamin K such as spinach, greens (collards, turnip, mustard etc.) and broccoli. Limit does not mean avoid. A balanced diet should include these foods in moderation. One of the problems with greens is that they are seasonal and tend to be over consumed during season especially in the South. While there appears to be no study directly linking DVT to availability of greens more DVT cases occur during the cold season (when greens are most available) than warm season. (3)
Dehydration is often overlooked as a cause of DVT. While researching this article and looking for potential causes of my own DVT, dehydration does appear to be a contributing factor. Keeping hydrated and maintaining electrolyte levels help reduce your chances of developing a DVT. Other causes of hypercoagulability where a physician’s help is needed are Genetic predisposition, increased red blood cell count and cancer.
Trauma to veins may not be avoidable but, awareness that trauma is a major cause of DVT can help you avoid the pain and potentially fatal consequences of DVT. There are few early signs of a developing clot . The sudden appearance of tortured (varicose) veins, swelling of the calf muscle, a dull ache more noticeable in one leg than the other while standing or sitting (especially on a hard chair or stool), tenderness in the leg/calf, discoloration of the leg below the area of the trauma and gorging or dilation of the surface veins in the calf may be noticeable in some cases. (4) Unfortunately, none of these symptoms may be noticeable until there is a complete blockage and other conditions, infection and muscle bruising for example, can cause similar symptoms. This complicates DVT diagnosis in early stages.
Typical treatment of DVT is generally limited to anticoagulant medication in all but life or limb threatening situations. Treatment starts with Low Molecular Weight Heparin (LMWH) injections for the first five days or so of treatment while the anticoagulant Warfarin is taken orally to establish an INR level of 2.0 to 3.0 or two to three times the normal INR. Establishing a stable INR with Warfarin typically takes four to seven days and regular monitoring of INR is needed to adjust dosage as required to maintain a stable INR. The anticoagulants do not dissolve the clot but may create blood conditions where the body can produce natural clot dissolving agents.
In life threatening cases, thrombolytic (clot dissolving drugs also called colt busters) medications such as tissue Plasminogen Activators (tPA), can be used to reduce the clot, though adverse side effects greatly limit the use of this treatment to pulmonary embolism, stroke and myocardial infarction cases. A trial using direct intraclot lacing with tPA conducted by Richard Chang, MD, had a 80% success rate in dissolving clots with little adverse side effects. That trial only involved 20 patients, so further study is required for this procedure to be accepted for DVT treatment. Surgical removal of the clot is rare and still controversial. The controversy is apparently due to vein valves damaged by the initial clot causing the pain and other symptoms of the DVT to persist even after the clot is removed.
Recovery times vary greatly and are impossible to accurately predict. For smaller clots caught early recovery time can be less than two weeks. Larger clots are much more difficult to fully recover from. Since there is a low likelihood that a large clot will fully dissolve with current treatments, recovery generally requires getting used to some pain, which can be substantial. Even if the clot dissolves or partially dissolves to allow some flow, valves in the vein are often damaged limiting the level of recovery. Exercise improves recovery time but should not be overdone. Daily walking or swimming until a reasonable pain threshold is met is desirable. Hourly or more often exercising of the calf muscle blood pump is also recommended. Consult your physician to determine which and how much exercise is appropriate for your current stage of treatment. Improvement may be slow, but you should notice some improvement within a few weeks even with a large clot. When in pain simply sitting with your calf elevated above your hip will provide nearly instantaneous relief. Even when reclining you can exercise the calf muscle blood pump by alternately pointing your toes away from you then trying to point them back at your knee for a few minutes every half hour or so.
Approximately 30 percent of DVT patients develop Post Thrombotic Syndrome (PTS) where DVT symptoms persist after treatment. PTS can develop anytime after treatment with most cases occurring within the first six months though it can occur years after treatment. Damaged valves in the vein is the typical cause of PTS. Persistence of the clot partially blocking blood flow can also cause PTS. DVT patients also have a greater risk of having another DVT within five years of their first DVT.
Prevention and early detection is much more desirable than treatment of a complete blockage of a deep vein. Ask your physician to include a PT/INR test with your physical, stay hydrated, avoid excessive vitamin K in your diet unless recommend by your physician and try to quit smoking. Like hypertension, DVT is a silent killer. Few symptoms of a developing clot are apparent though increased awareness may make the often subtle early symptoms more noticeable.
For more information visit stoptheclot.org and should you or a loved one develop DVT, an online support group is available at dailystrength.org.
This article has not been reviewed by and is not indorsed by Associated Content. The author is not a physician. Consult a physician if you have or believe you are at higher risk of developing a DVT.