Deep Vein Thrombosis Signs and Symptoms

Deep Vein Thrombosis Signs and Symptoms


What is deep vein thrombosis?

Deep venous thrombosis is a blood clot that forms in a vein deep inside a part of the body. It mainly affects the large veins in the lower leg and thigh.

Symptoms of deep vein thrombosis

Deep vein thrombosis signs and symptoms can include:

  • Swelling in the affected leg. Rarely, there may be swelling in both legs.
  • Pain in your leg. The pain often starts in your calf and can feel like cramping or a soreness.
  • Deep vein thrombosis may sometimes occur without any noticeable symptoms.

What are the causes of deep vein thrombosis?

Blood is meant to flow. If it becomes stagnant, there is a potential for it to clot. The blood in veins constantly forms microscopic clots that are routinely broken down by the body. If the balance of clot formation and resolution is altered, significant clotting can occur. A thrombus can form if one or a combination of the following situations is present.


  • Prolonged travel and sitting, such as long airplane flights (“economy class syndrome”), car, or train travel
  • Hospitalization
  • Surgery
  • Trauma to the lower leg with or without surgery or casting
  • Pregnancy, including 6-8 weeks post partum
  • Obesity

Hypercoagulability (coagulation of blood faster than usual)

  • Medications (for example,birth control pills, estrogen)
  • Smoking
  • Genetic predisposition
  • Polycythemia (increased number of red blood cells)
  • Cancer

Trauma to the vein

  • Fracture to the leg
  • Bruised leg
  • Complication of an invasive procedure of the vein

Who is at risk?

Each year, 1 in every 1,000 people in the UK is affected by deep vein thrombosis.

Deep Vein Thrombosis Signs and Symptoms

Anyone can develop deep vein thrombosis, but it becomes more common with age. As well as age, risk factors include:

  • previous venous thromboembolism
  • a family history of blood clots
  • medical conditions such as cancer and heart failure
  • inactivity.  for example, after an operation
  • being overweight or obese

Risk factors for deep vein thrombosis

Some of the risk factors that may contribute to the formation of a thrombus include:

  • coronary heart disease
  • being overweight or obese
  • cigarette smoking
  • pregnancy
  • a high-dose combined oral contraceptive pill
  • a susceptibility to ‘stickier’ blood and a family history of deep vein thrombosis
  • blood clotting disorders
  • sitting still for long periods of time
  • recent surgery or injury
  • some types of cancer
  • congestive cardiac failure
  • previous thrombosis
  • hormone therapy.

Treating deep vein thrombosis

Treatment for deep vein thrombosis usually involves taking anticoagulant medicines, which help reduce the ability of the blood to clot.
You will also be prescribed compression stockings to wear every day, as these help prevent complications and improve symptoms.