Deep vein thrombosis - What will happen to me?
BMJ Group Medical Reference
Deep vein thrombosis (DVT) can be dangerous. So it's very important to go to your doctor if you have any symptoms of DVT.
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.Blood clots that are above the knee are more likely to lead to a pulmonary embolism, which is dangerous. It happens when a blood clot travels to one of your lungs and gets stuck in an artery that brings blood to this lung.
So if your doctor thinks you have a clot in your calf, it's important to get this checked in seven days to see whether the clot has travelled 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.
Each year, about 1 in 4 people who have a clot below the knee get another one. 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.
A large review of studies looked at nearly 12,000 people diagnosed with DVT and treated for six months. It found: that:
DVT is less likely to come back if it happened after you had an operation. In one study looking at how often people got a second DVT:
There was a less than 1 in 100 chance of having a DVT each year for people who'd had their first DVT after an operation
There was a 7 in 100 chance of having a DVT each year for people who'd had their first DVT without an obvious cause.
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.