What is deep vein thrombosis (DVT)?
Deep vein thrombosis (DVT) is a blood clot. These clots usually occur deep down in your leg veins. DVT is common and can be dangerous. If the blood clot breaks off and travels through your bloodstream, it can block a blood vessel in your lungs. This blockage (called a pulmonary embolism) can be fatal.
Symptoms of DVT
Some people who have DVT do not have any symptoms. Most have some swelling in one or both legs. Often, there is pain or tenderness in one leg (may happen only when you stand or walk). Your skin may feel warm or look red or discolored. If you have any of these symptoms, call your doctor right away.
What causes DVT?
Often, there are multiple factors that cause DVT. Your risk for DVT increases if you have several risk factors at the same time. You are at higher risk for DVT if you:
- Are 60 years of age or older.
- Are inactive for a long period of time, such as when you are flying in an airplane, taking a long car trip, or recovering in bed after surgery.
- Have a condition that causes increased blood clotting.
- Have an injury or surgery that reduces blood flow to a body part.
- Have a central venous catheter.
- Are pregnant or have recently given birth.
- Are overweight or obese.
- Have varicose veins or vasculitis.
- Have cancer.
- Are a smoker.
- Take birth control pills or receive hormone therapy, including for postmenopausal symptoms.
How is DVT diagnosed?
Visit your doctor if you think you might have DVT. They will review your symptoms and health history and do a physical exam. They may order tests to help diagnose it. An ultrasound is the most common test. It uses sound waves to check the blood flow in your veins. A venography also can be done to find blood clots. A doctor injects dye into your veins and then takes an X-ray to check your blood flow.
Can DVT be prevented or avoided?
There are several things you can do to help prevent DVT. These are more important if you are at increased risk.
- Get frequent exercise. If you are inactive for a long period of time, move your legs around. Get up every hour or so and walk around, if you can. If you must stay seated, do lower leg exercises. With your feet flat on the ground, alternate lifting your heels and toes. This stretches your calves and keeps up your blood flow.
- Stretch your legs and lightly massage your muscles.
- Get out of bed and move around as soon as you can after being ill or having surgery.
- Control your blood pressure.
- Do not smoke.
- Lose weight if you are overweight.
The main goals of DVT treatment are to:
- Stop the clot from getting bigger.
- Prevent the clot from breaking off and traveling to your lungs.
- Prevent future blood clots.
Several medicines are used to treat and prevent DVT. Common ones include warfarin or heparin. These thin your blood so that clots won’t form. Warfarin is taken as a pill and heparin is given intravenously (in your veins). Warfarin can cause birth defects. Women who are pregnant should not take warfarin. If you can’t take heparin, your doctor may prescribe another type called a thrombin inhibitor. Newer treatment programs recommend NOACs (novel oral anticoagulants) as preferable medicines in most settings. Brand names include Eliquis, Pradaxa, and Xarelto.
Anticoagulants can cause you to bleed more easily. For example, you might notice that your blood takes longer to clot when you cut yourself. You may bruise more easily as well. If you have any unusual or heavy bleeding, call your doctor right away.
Some other medicines can affect how well an anticoagulant works. Talk to your doctor before you take any new medicine. This includes over-the-counter medicines and vitamins. Certain foods rich in vitamin K, such as dark green vegetables, also can have an effect.
There are other treatment options if you can’t take medicine to thin your blood, or if a blood thinner doesn’t work. Your doctor may suggest putting a filter in your vena cava. This is the main vein that carries blood from your lower body to your heart. This filter can catch a clot as it moves through your bloodstream and prevent it from reaching your lungs. This treatment is more common for people who have had several blood clots travel to their lungs.
Living with DVT
It is important to start treatment right away for DVT. It takes about 3 to 6 months for a blood clot to go away. During this time, there are things you can do to relieve symptoms. Elevate your leg to reduce swelling. Talk to your doctor about using compression stockings. These cover the arch of your foot up to your knee. They create pressure on your leg to reduce swelling and relieve pain.
For some people, the clot may never fully dissolve. This can cause scar tissue in your veins. DVT also can lead to post-thrombotic syndrome. People who get this have chronic (long-term) swelling and pain.
If you have DVT and experience the following symptoms, get help right away. These are signs that the clot may have traveled to your lungs. You could be having a pulmonary embolism.
- shortness of breath
- chest pain
- rapid heart rate
- coughing blood
Questions to ask your doctor
- What is the likely cause of my DVT?
- What is the best treatment for me?
- How long do I need to take anticoagulants? What are the side effects or risks?
- Can I drink alcohol or exercise while using anticoagulants?
- Are there any lifestyle changes I can make to reduce my risk of blood clots?
- If I have DVT once, what is my risk of having future blood clots?
- Is it safe for me to travel?
- Does DVT increase my risk for other health problems?