- Pain in the leg
- Tenderness in the calf (this is one of the most important signs)
- Leg tenderness
- Swelling of the leg
- Increased warmth of the leg
- Redness in the leg
- Bluish skin discoloration
- Discomfort when the foot is pulled upward
THEN YOU ARE SUFFERING FROM DVT. So what is DVT?
Deep Vein Thrombosis (DVT)
Deep Vein Thrombosis is a common disorder relating to the formation of blood clots in major veins. It can affect people of any age but the risk of developing a DVT increases after the age of 40 years. DVT has been linked in recent years with long distance air travel.
Life-threatening complications can arise from DVT when blood clots dislodge, travelling through the body and lodging in other veins or arteries, forming an embolism. This can be life threatening, especially when the embolism occurs in the lungs, heart or brain. Pulmonary embolism (a blood clot in the lung) is the most common of these serious DVT complications.
Veins are blood vessels that carry blood from the tissues of the body back to the heart. Veins that lie just beneath the skin surface are referred to as “superficial veins” while veins found deep inside the muscles are referred to as “deep veins”. Other veins connect the superficial and deep veins, allowing blood to flow between them.
When a blood clot occurs in a vein it is referred to as a venous thrombosis. A deep vein thrombosis (DVT) is a blood clot that occurs in the deep veins. DVTs can occur in any of the deep veins but most commonly occur in the leg and pelvic veins. The clot will either partially or completely block the flow of blood through the affected vein. When the blood clot is associated with inflammation of the vein it is referred to as thrombophlebitis.
A DVT is usually more serious than a blood clot in one of the superficial veins, as there is a much greater risk that part of the clot may dislodge and circulate through the body.
A DVT is more likely to occur when the blood flow through the deep veins is slowed or where there is some factor that makes the blood more likely to clot.
General factors that increase the risk of developing a DVT include:
- Having previously had a DVT
- Having a family member who has had a DVT.
Factors that can slow the blood flow include:
- Immobility – blood flow is slowed when a person remains immobile for long periods of time. Situations where this can occur include:
o Paralysis eg: following a stroke or injury
o Being bedridden eg: following surgery or due to illness
o Having a leg in a plaster cast or splint
o Sitting for long periods of time while travelling eg: in a bus, plane or car. “Economy class syndrome” is a term that has been used to describe a reported increased incidence of DVTs after long distance plane flights. The level of this increased risk continues to be debated.
- Injury to a vein eg: as a result of a broken bone or severe muscle injury.
- Surgery – particularly orthopaedic and cancer surgery
- Heart disease – particularly heart failure
- Varicose veins
- Phlebitis (inflammation of the walls of the vein)
Factors that can make the blood more likely to clot:
- Hormone medications – some research studies have indicated that there may be an increased risk of DVT associated with some types of oestrogen-containing oral contraceptive pills, as well as some hormone replacement therapies (HRT).
- Inherited disorders – such as the deficiency of some blood clotting factors eg: protein C; or defective blood clotting factors eg: Factor V Leiden
- Inflammatory bowel diseases eg: Crohn’s disease
- Certain cancers
Deep vein thrombosis (DVT) is the formation of a blood clot, known as a thrombus, in the deep leg vein. It is a very serious condition that can cause permanent damage to the leg, known as post-thrombotic syndrome, or a life-threating pulomnary embolism. In the United States alone, 600,000 new cases are diagnosed each year. One in every 100 people who develops DVT dies. Recently, it has been referred to as “Economy Class Syndrome” due to the occurrence after sitting on long flights.
The deep veins that lie near the center of the leg are surrounded by powerful muscles that contract and force deoxygenated blood back to the lungs and heart. One-way valves prevent the back-flow of blood between the contractions. (Blood is squeezed up the leg against gravity and the valves prevent it from flowing back to our feet.) When the circulation of the blood slows down due to illness, injury or inactivity, blood can accumulate or “pool,” which provides an ideal setting for clot formation.
- Previous DVT or family history of DVT
- Immobility, such as bed rest or sitting for long periods of time
- Recent surgery
- Above the age of 40
- Hormone therapy or oral contraceptives
- Pregnancy or post-partum
- Previous or current cancer
- Limb trauma and/or orthopedic procedures
- Coagulation abnormalities
- Discoloration of the legs
- Calf or leg pain or tenderness
- Swelling of the leg or lower limb
- Warm skin
- Surface veins become more visible
- Leg fatigue
Post-thrombotic syndrome is an under-recognized, but relatively common sequela, or aftereffect, of having DVT if treated with blood thinners (anticoagulation) alone, because the clot remains in the leg. Contrary to popular belief, anticoagulants do not actively dissolve the clot, they just prevent new clots from forming. The body will eventually dissolve a clot, but often the vein becomes damaged in the meantime. A significant proportion of these patients develop permanent irreversible damage in the affected leg veins and their valves, resulting in abnormal pooling of blood in the leg, chronic leg pain, fatigue, swelling, and, in extreme cases, severe skin ulcers. While this use to be considered an unusual, long-term sequela, it actually occurs frequently, in as many as 60-70 percent of people, and can develop within two months of developing DVT. There is increasing evidence that clot removal via interventional catheter-directed thrombolysis in selected cases of DVT can improve quality of life and prevent the debilitating sequela of post-thrombotic syndrome.
Left untreated, a deep vein thrombosis (DVT) can break off and travel in the circulation, getting trapped in the lung, where it blocks the oxygen supply, causing heart failure. This is known as a pulmonary embolism, which can be fatal. With early treatment, people with DVT can reduce their chances of developing a life threatening pulmonary embolism to less than one percent. Blood thinners like heparin and coumadin are effective in preventing further clotting and can prevent a pulmonary embolism from occurring.
- It is estimated that each year more than 600,000 patients suffer a pulmonary embolism.
- PE causes or contributes to up to 200,000 deaths annually in the United States.
- One in every 100 patients who develop DVT die due to pulmonary embolism.
- A majority of pulmonary embolism are caused by DVT.
- If pulmonary embolism can be diagnosed and appropriate therapy started, the mortality can be reduced from approximately 30 percent to less than ten percent.
Symptoms of Pulmonary Embolism
The symptoms are frequently nonspecific and can mimic many other cardiopulmonary events.
- Shortness of breath
- Rapid pulse
- Sharp chest pain
- Bloody sputum (coughing up blood)