Deep Venous Thrombosis (DVT)
What is a deep venous thrombosis (DVT)?
A deep venous thrombosis (DVT) is a blood clot that forms in a vein deep inside the body (Figure 1). DVTs can occur in other parts of the body (see Figure 2 and Figure 3), but they mainly affect the larger veins of the lower leg and thigh. DVTs can form if the vein’s lining is damaged, blood flow is slow, or the blood is thicker than normal.
A deep venous thrombosis (DVT) is a blood clot that forms in a vein deep inside the body (Figure 1). DVTs can occur in other parts of the body (see Figure 2 and Figure 3), but they mainly affect the larger veins of the lower leg and thigh. DVTs can form if the vein’s lining is damaged, blood flow is slow, or the blood is thicker than normal.
Who is at risk for a DVT?
Blood clots form when something slows the blood flow or changes the way the blood flows through the veins. The risk factors include bed rest, a family history of blood clots, fractures in the pelvis or legs, giving birth in the last 6 months, obesity, recent surgery, a history of smoking, cancer, autoimmune disorders, and taking birth control pills. While DVTs can happen to anyone at any age, they are most common in adults over 60 years of age.
Blood clots form when something slows the blood flow or changes the way the blood flows through the veins. The risk factors include bed rest, a family history of blood clots, fractures in the pelvis or legs, giving birth in the last 6 months, obesity, recent surgery, a history of smoking, cancer, autoimmune disorders, and taking birth control pills. While DVTs can happen to anyone at any age, they are most common in adults over 60 years of age.
What are the signs/symptoms of a DVT?
While there are some signs of a DVT, only about half of the people how have DVTs are symptomatic. The signs of a DVT include changes in skin color like erythema (redness), leg pain, leg swelling, and increased warmth in the area of the leg that is swollen or painful.
While there are some signs of a DVT, only about half of the people how have DVTs are symptomatic. The signs of a DVT include changes in skin color like erythema (redness), leg pain, leg swelling, and increased warmth in the area of the leg that is swollen or painful.
Figure 4. This picture shows redness and swelling of a patient's left thigh from the restricted blood flow caused by a DVT. Adapted from A.D.A.M. Medical Encyclopedia, D. Dugdale, 2013, Retrieved April 27, 2014 from Figure 1. DVTs involve the formation of clot in a large, deep vein. Adapted from A.D.A.M. Medical Encyclopedia, D. Dugdale, 2013, Retrieved April 27, 2014 from http://www.nlm.nih.gov/medlineplus/ency/imagepages/8984.htm
How is a DVT diagnosed and how is it treated?
A physical examination may reveal erythema, edema, or tenderness to palpation of the affected leg. Lab testing would be completed and may include a d-dimer blood test. The d-dimer test measures a substance in the blood that is released when a blood clot dissolves; if the test is positive, a DVT is a possibility but cannot be confirmed with the d-dimer result alone. A doppler ultrasound of the affected extremity is completed to evaluate the blood flow in the veins. If a doppler ultrasound does not reveal a clear diagnosis, venography (a type of x ray) can be used to evaluate the presence of a clot.
The treatment of a DVT involves the use of anticoagulant drugs to thin the blood. The anticoagulant will prevent more clots from forming and prevent the growth of old clots. Heparin is typically the first drug that is administered and warfarin is usually started with it. Usually, it is also recommended that the patient begin wearing compression stockings to improve blood flow in the legs. In severe cases, surgery may be warranted to remove the clot or place a filter to prevent clots from traveling to the lungs.
A physical examination may reveal erythema, edema, or tenderness to palpation of the affected leg. Lab testing would be completed and may include a d-dimer blood test. The d-dimer test measures a substance in the blood that is released when a blood clot dissolves; if the test is positive, a DVT is a possibility but cannot be confirmed with the d-dimer result alone. A doppler ultrasound of the affected extremity is completed to evaluate the blood flow in the veins. If a doppler ultrasound does not reveal a clear diagnosis, venography (a type of x ray) can be used to evaluate the presence of a clot.
The treatment of a DVT involves the use of anticoagulant drugs to thin the blood. The anticoagulant will prevent more clots from forming and prevent the growth of old clots. Heparin is typically the first drug that is administered and warfarin is usually started with it. Usually, it is also recommended that the patient begin wearing compression stockings to improve blood flow in the legs. In severe cases, surgery may be warranted to remove the clot or place a filter to prevent clots from traveling to the lungs.
Why is a DVT a life threatening condition?
An embolism occurs when a clot breaks off and moves through the blood stream. Embolisms can get stuck in the brain, lungs, heart, or other area of the body causing severe damage and even death.
An embolism occurs when a clot breaks off and moves through the blood stream. Embolisms can get stuck in the brain, lungs, heart, or other area of the body causing severe damage and even death.
Sources
Dugdale, D. (2013). Deep venous thrombosis. In A.D.A.M. Medical Encyclopedia. Retrieved April 27, 2014 from
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001209/
Huisman, M., & Klok, F. (2013). Diagnostic management of acute deep vein thrombosis and pulmonary embolism. Journal Of
Thrombosis And Haemostasis: JTH, 11(3), 412-422. doi:10.1111/jth.12124
Linkins, L., Bates, S., Lang, E., Kahn, S., Douketis, J., Julian, J., & ... Kearon, C. (2013). Selective D-dimer testing for diagnosis of
a first suspected episode of deep venous thrombosis: a randomized trial. Annals Of Internal Medicine, 158(2), 93-100.
doi:10.7326/0003-4819-158-2-201301150-00003
Dugdale, D. (2013). Deep venous thrombosis. In A.D.A.M. Medical Encyclopedia. Retrieved April 27, 2014 from
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001209/
Huisman, M., & Klok, F. (2013). Diagnostic management of acute deep vein thrombosis and pulmonary embolism. Journal Of
Thrombosis And Haemostasis: JTH, 11(3), 412-422. doi:10.1111/jth.12124
Linkins, L., Bates, S., Lang, E., Kahn, S., Douketis, J., Julian, J., & ... Kearon, C. (2013). Selective D-dimer testing for diagnosis of
a first suspected episode of deep venous thrombosis: a randomized trial. Annals Of Internal Medicine, 158(2), 93-100.
doi:10.7326/0003-4819-158-2-201301150-00003