Deep Vein Thrombosis

Deep vein thrombosis is a medical condition in which there is a blood clot that is thrombus formation in one or more of the deep veins in the body, usually in the legs. Deep vein thrombosis may not present with any symptoms however in some patients can cause pain in the leg or swelling. Deep vein thrombosis is a serious condition because blood clots in the veins can break loose, travel through the bloodstream, and obstruct the lungs, blocking blood flow. The cause of deep vein thrombosis is explained by the Virchow triad.

The patient with deep vein thrombosis may not present with any symptoms. Some patients present with swelling of the legs, pain, difficulty in walking, and bluish discoloration of the affected area. Warning signs like chest pain and difficulty in breathing indicate the development of pulmonary embolism.

Confirmation is done based on the blood levels of D dimer and imaging tests which confirm the presence of a clot. Treatment of the condition mainly involves anticoagulants, compression stocks, thrombolytic therapy, and lifestyle modifications.

Deep Vein Thrombosis: Causes

Various factors play an important role in the development of Deep vein thrombosis. Virchow triad explains the causes of DVT. Virchow triad includes −

  • Venous stasis

  • Endothelial damage

  • Hypercoagulable state

Factors causing venous stasis include −

  • Prolonged bed rest usually more than 48 hours such as a cast on the leg, Limb paralysis from stroke, spinal cord injury, and extended travel in a vehicle

  • Hypercoagulability state secondary to Surgery and trauma contributes to 40% of all thrombi embolic disease, Malignancies, Increased estrogen levels

  • Inherited disorders of coagulation such as Deficiencies of protein-S, protein-C, and anti-thrombin Acquired disorders of coagulation such as Nephrotic syndrome, Antiphospholipid antibodies

  • Factors resulting in Endothelial Injury include Trauma, surgery, Invasive procedure, Iatrogenic causes central venous catheters

  • Certain medical conditions can increase the risk of DVT such as cancer, heart disease, obesity, and autoimmune disorders such as lupus.

  • Certain medications such as hormone replacement therapy and birth control pills can also increase the risk of DVT.

  • Genetics also play a role in increasing the risk of DVT

Deep Vein Thrombosis: Symptoms

Patients with deep vein thrombosis mainly present with the following symptoms that include −

  • The more common complaint is the swelling or edema of the legs where the thrombosis has happened. This swelling can be sudden and severe or gradual and may be accompanied by pain or tenderness in the affected area.

  • Some patients present with pain in the affected area, that worsens when standing or walking. The pain can be cramp, aching, or soreness in nature

  • The veins over the affected area become more visible, as blood flow is obstructed by the clot.

  • Difficulty in walking or standing due to the pain, swelling, and discomfort in the affected leg.

  • The skin over the affected area may become red and warm to the touch, indicating inflammation caused by the clot.

  • The skin over the affected area becomes bluish or reddish hue.

  • If there is a pulmonary embolism due to the broken thrombus traveling to the lungs through the bloodstream then the patients present with chest pain, shortness of breath, and difficulty breathing.

Deep Vein Thrombosis: Risk Factors

Several factors play an important role in the development of deep vein thrombosis which includes −

  • People over 60yrs of age

  • A family history of DVT or other blood clotting disorders can increase the risk of DVT.

  • Long periods of inactivity or immobility such as in paralysis patients.

  • The person who has undergone Major surgeries, particularly of the lower limbs, abdomen, or pelvis, can increase the risk of DVT.

  • Use of birth control pills that is oral contraceptive pills or hormone replacement therapy

  • Pregnancy and childbirth can increase the risk of DVT due to changes in blood flow and hormonal factors.

  • Obesity, Smoking, Cancer

  • Certain medical conditions such as heart disease, stroke, and inflammatory bowel disease can increase the risk of DVT.

Deep Vein Thrombosis: Diagnosis

The diagnosis of deep vein thrombosis is mainly done based on history, and physical examination, and some of the tests required for confirmation include −

  • History of swelling of the leg, and difficulty in walking, associated with pain and bluish discoloration arise suspicion of the disease

  • Physical examination to look for signs of swelling, pain, tenderness, and discoloration. suggest the presence of DVT

  • Blood test is done to measure the levels of a protein called D-dimer in the blood. But this is not the confirmatory test that needs combination with imaging tests for the confirmation of DVT

  • Duplex ultrasound is a non-invasive imaging test that uses sound waves to create an image of the veins and detect the presence of blood clots.

  • Magnetic resonance imaging can also help to get detailed images of the veins and detect blood clots.

  • Computed tomography (CT) scan can also show the presence of the clot

Deep Vein Thrombosis: Treatment

The treatment of deep vein thrombosis mainly aims at thinning the blood and preventing blood clot formation. In some cases, removal of the clot is advised to prevent it from traveling to the lungs.

Conservative Treatment

Conservative treatment includes −

  • Anticoagulants such as heparin and warfarin are the mainstay of the treatment for DVT.

  • Compression stockings are tight-fitting stockings that help to improve blood flow in the legs and reduce the risk of complications from DVT

  • Thrombolytic therapy can be advised with a large clot or severe symptoms.

  • An IVC filter is a small device that is inserted into the inferior vena cava, the main vein in the abdomen, to prevent blood clots from traveling to the lungs.

  • Lifestyle modifications such as regular exercise, maintaining a healthy weight, quitting smoking, and avoiding prolonged periods of inactivity, can help to prevent DVT from occurring or recurring.

Surgical Treatment

Surgical removal of the clot may be required in severe cases where the risk of pulmonary embolism is more.

Deep Vein Thrombosis: Prevention

Some of the measures that can help to prevent deep vein thrombosis include −

  • Avoid long periods of sitting or standing

  • Regular activities like walking, stretching, or leg exercises can help to improve blood flow and reduce the risk of blood clots.

  • Following a healthy diet, regular exercises, and maintaining a healthy body weight

  • Avoid smoking

  • Drink plenty of water and fluids to stay hydrated.

  • Compression stockings help to improve blood flow and reduce the risk of blood clots


Deep vein thrombosis is a condition in which there is a thrombus or blood clot formation in the veins secondary to various factors leading to venous stasis, hypercoagulability, and endothelial injury. The main causes include prolonged immobilization, after major surgeries of the legs and abdomen, certain hypercoagulability disorders, and genetics. The patient presents with swelling of the leg with associated pain and bluish discoloration of the skin around the affected area.

The condition is diagnosed based on history, physical examination, and investigations like imaging tests to look for the presence of the clot and blood levels of D dimer. Treating the condition on time and regular intake of the medicine is important to prevent the occurrence of pulmonary embolism which is life-threatening.

Dr. Durgesh Kumar Sinha
Dr. Durgesh Kumar Sinha


Updated on: 28-Apr-2023


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