The most obvious symptoms of deep vein thrombosis (DVT) are swelling or pain in the calf or thigh of one leg, or both swelling and pain. To learn more, see What are the symptoms of deep vein thrombosis?

In about 1 in 2 people who have a clot that starts in their calf, the clot spreads to above their knee.

 

 

 

 

 

Source:
Kakkar VV, Howe CT, Flanc C, et al.
Natural history of postoperative deep vein thrombosis.
Lancet. 1969; 2: 230-232.

 

 

 

 

 

¹ Blood clots that are above the knee are more likely to lead to a

 

 

 

 

 

pulmonary embolism
A pulmonary embolism can give you chest pain, make you feel breathless and uncomfortable or make you breathe rapidly. A pulmonary embolism is dangerous and can kill you if it is not treated.

 

 

 

 

 

pulmonary embolism, which is dangerous. Pulmonary embolism happens when a blood clot travels to one of your lungs and gets stuck in an

 

 

 

 

 

arteries
Arteries are the blood vessels that take blood that is rich in oxygen and food away from your heart. The arteries carry this blood to all the tissues in your body.

 

 

 

 

 

artery that brings blood to this lung.

So if your doctor thinks you have a clot in your calf, it's important to have a check again in seven days to see whether the clot has traveled above your knee.

Without treatment, in about 1 in 10 people with a clot above their knee, the clot will lodge in the artery of a lung (a pulmonary embolism). And as many as 1 in 10 people who get a pulmonary embolism die.

 

 

 

 

 

Source:
Ibrahim SA, Stone RA, Obrosky DS, et al.
Racial differences in 30-day mortality for pulmonary embolism.
American Journal of Public Health. 2006; 96: 2161-2164.

 

 

 

 

 

²

Each year, about 1 in 4 people who have a clot below the knee get another one.

 

 

 

 

 

Source:
Lagerstedt C, Olsson C, Fagher B, et al.
Need for long-term anticoagulant treatment in symptomatic calf-vein thrombosis.
Lancet. 1985; 334: 515-518.

 

 

 

 

 

³

 

 

 

 

 

Source:
Lohr J, Kerr T, Lutter K, et al.
Lower extremity calf thrombosis: to treat or not to treat?
Journal of Vascular Surgery. 1991; 14: 618-623.

 

 

 

 

 

⁴ DVT is more likely to come back if you have a blood-clotting problem or cancer. If you have cancer, your blood may tend to clot more. This can be caused either by the disease or by the treatment for it.

You are less likely to get DVT again if it happened after you had an operation.

 

 

 

 

 

Source:
Prandoni P, Lensing AW, Cogo A, et al.
The long-term clinical course of acute deep venous thrombosis.
Annals of Internal Medicine. 1996; 125: 1-7.

 

 

 

 

 

⁵

Following DVT, you can get swelling, open sores (

 

 

 

 

 

ulcer
An ulcer is an open sore. Ulcers can happen in many parts of your body, such as in your stomach, and the skin of your legs, mouth or genitals.

 

 

 

 

 

ulcers) and permanent damage to tissue around the blocked vein. Doctors call this post-thrombotic syndrome. You are more likely to get this if the clot is above your knee.

In some people, DVT may clear up on its own, without treatment. Some people may never even know they had DVT. Still, if you are worried that you might have DVT, you should see your doctor at once.

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