Deep vein thrombosis

The condition in which a blood clot forms in the body’s deep veins is called Deep Vein Thrombosis (DVT). Clots form when blood thickens and clumps together. DVT occurs most often in the deep veins of the leg and thighs.

Causes of DVT include:

  • Sitting for a long time, such as when travelling by car or plane
  • Prolonged bed rest or long hospital stay
  • Post-operative nerve injury
  • Certain medical conditions, including cancers, pregnancy, smoking, obesity, heart failure, and others

Symptoms occur in the affected leg and include:

  • Pain or tenderness in the leg
  • Swelling of the leg
  • Increased warmth over the affected area
  • Changes in skin colour

Your doctor will diagnose DVT based on the medical history, physical examination, and test results. Medical history includes your overall health status, surgical history, and personal history. During the physical exam, your doctor will check your legs for swelling, tenderness, or skin discolouration.

Your doctor may recommend a few tests, such as:

  • D-dimer blood test
  • Ultrasound of the legs
  • CT or MRI scan to provide a clearer picture of the veins

Treatment options include conservative and surgical measures:


  • Medications: Your doctor may prescribe anticoagulants (or blood thinners) that reduce the blood’s ability to clot. The role of these medications is to prevent the clot from getting bigger. Thrombolytics (or clot busters) to help break the clots are prescribed only in life-threatening conditions.
  • Compression stockings are designed to help prevent blood clots from developing in the deep veins of the leg. The stocking creates pressure and improves the blood flow in the legs, and reduces the risk of developing blood clots.


  • Surgery is the last treatment option considered when the above conservative measures fail to reduce the symptoms of DVT. Surgery is the preferred treatment to remove large blood clots.


Untreated cases of DVT can lead to pulmonary embolism (PE). PE is a serious condition in which the blood clots break (known as embolus), travel through the blood circulation and lodges in the lung, blocking the blood flow.

Post-phlebitic syndrome (PPS) is a chronic complication of DVT and is characterised by swelling, skin discolouration, and pain in the affected leg.

If you are at risk of developing DVT, you can help prevent by:

  • Visiting your doctor regularly
  • Taking the prescribed medications
  • Wearing compression stockings
  • Stretching your legs while travelling or sitting for a long time
  • Lifestyle modifications such as weight control and quitting smoking