Venous thromboembolism

About a DVT

Why does blood clot?

Blood clots occur as a vital protection system in our body. When we injure or cut ourselves, a clot is formed outside of our veins to protect us from the loss of blood. This is a natural process known as the clotting cascade. However, there are times when the clotting cascade goes wrong and blood clots form inside our veins, causing a DVT.

What are the causes and symptoms of a DVT?

Certain people are more likely to develop a DVT than others. Risk factors include:

  • age - older people are more likely to have a DVT than younger people
  • immobility caused by long travel journeys, illnesses or injuries
  • having a recent operation
  • pregnancy
  • having severe pre-existing medical illnesses such as cancer, heart problems or respiratory disease
  • previous experience of a DVT
  • taking hormone-based treatment, such as the contraceptive pill and hormone replacement therapy
  • obesity.

Some people with a DVT may have no symptoms, but common symptoms of a DVT are:

  • tenderness in the leg
  • redness
  • swelling and a feeling of tightness, the skin may feel stretched
  • pain.

Some people may only realise they have a DVT when a PE develops as a result of the clot travelling to the lungs. Symptoms of a PE include:

  • chest pain that is sharp and is worse when taking a deep breath
  • shortness of breath
  • sweating.

What can I do to reduce the chance of having a DVT?

It is important to listen to the medical team looking after you once you’ve had an op eration and move around when you are asked to. If you can’t move easily after the operation you may be asked to do leg exercises. You may also be offered elastic compression stockings or a mechanical foot pump in order to help blood flow in your leg. Drink plenty of fluids if you are able to and if you experience any leg or chest symptoms, tell your doctor or a nurse immediately.