Deep Vein Thrombosis

ExitCare ImageA deep vein thrombosis (DVT) is a blood clot that develops in a deep vein. A DVT is a clot in the deep, larger veins of the leg, arm, or pelvis. These are more dangerous than clots that might form in veins near the surface of the body. A DVT can lead to complications if the clot breaks off and travels in the bloodstream to the lungs.

A DVT can damage the valves in your leg veins, so that instead of flowing upwards, the blood pools in the lower leg. This is called post-thrombotic syndrome, and can result in pain, swelling, discoloration, and sores on the leg.

Once identified, a DVT can be treated. It can also be prevented in some circumstances. Once you have had a DVT, you may be at increased risk for a DVT in the future.


Blood clots form in a vein for different reasons. Usually several things contribute to blood clots. Contributing factors include:

  • The flow of blood slows down.

  • The inside of the vein is damaged in some way.

  • The person has a condition that makes blood clot more easily.

Some people are more likely than others to develop blood clots. That is because they have more factors that make clots likely. These are called risk factors. Risk factors include:

  • Older age, especially over 75 years old.

  • Having a history of blood clots. This means you have had one before. Or, it means that someone else in your family has had blood clots. You may have a genetic tendency to form clots.

  • Having major or lengthy surgery. This is especially true for surgery on the hip, knee, or belly (abdomen). Hip surgery is particularly high risk.

  • Breaking a hip or leg.

  • Sitting or lying still for a long time. This includes long distance travel, paralysis, or recovery from an illness or surgery.

  • Cancer, or cancer treatment.

  • Having a long, thin tube (catheter) placed inside a vein during a medical procedure.

  • Being overweight (obese).

  • Pregnancy and childbirth. Hormone changes make the blood clot more easily during pregnancy. The fetus puts pressure on the veins of the pelvis. There is also risk of injury to veins during delivery or a caesarean. The risk is at its highest just after childbirth.

  • Medicines with the female hormone estrogen. This includes birth control pills and hormone replacement therapy.

  • Smoking.

  • ExitCare ImageOther circulation or heart problems.


When a clot forms, it can either partially or totally block the blood flow in that vein. Symptoms of a DVT can include:

  • Swelling of the leg or arm, especially if one side is much worse.

  • Warmth and redness of the leg or arm, especially if one side is much worse.

  • Pain in an arm or leg. If the clot is in the leg, symptoms may be more noticeable or worse when standing or walking.

The symptoms of a DVT that has traveled to the lungs (pulmonary embolism, PE) usually start suddenly, and include:

  • Shortness of breath.

  • Coughing.

  • Coughing up blood or blood-tinged phlegm.

  • Chest pain. The chest pain is often worse with deep breaths.

  • Rapid heartbeat.

Anyone with these symptoms should get emergency medical treatment right away. Call your local emergency services (911 in U.S.) if you have these symptoms.


If a DVT is suspected, your caregiver will take a full medical history and carry out a physical exam. Tests that also may be required include:

  • Blood tests, including studies of the clotting properties of the blood.

  • Ultrasonography to see if you have clots in your legs or lungs.

  • X-rays to show the flow of blood when dye is injected into the veins (venography).

  • Studies of your lungs, if you have any chest symptoms.


  • Exercise the legs regularly. Take a brisk 30 minute walk every day.

  • Maintain a weight that is appropriate for your height.

  • Avoid sitting or lying in bed for long periods of time without moving your legs.

  • Women, particularly those over the age of 35, should consider the risks and benefits of taking estrogen medicines, including birth control pills.

  • Do not smoke, especially if you take estrogen medicines.

  • Long distance travel can increase your risk of DVT. You should exercise your legs by walking or pumping the muscles every hour.

  • In-hospital prevention:

  • Many of the risk factors above relate to situations that exist with hospitalization, either for illness, injury, or elective surgery.

  • Your caregiver will assess you for the need for venous thromboembolism prophylaxis when you are admitted to the hospital. If you are having surgery, your surgeon will assess you the day of or day after surgery.

  • Prevention may include medical and nonmedical measures.


Treatment for DVT helps prevent death and disability. The most common treatment for DVT is blood thinning (anticoagulant) medicine, which reduces the blood's tendency to clot. Anticoagulants can stop new blood clots from forming and old ones from growing. They cannot dissolve existing clots. Your body does this by itself over time. Anticoagulants can be given by mouth, by intravenous (IV) access, or by injection. Your caregiver will determine the best program for you.

  • Heparin or related medicines (low molecular weight heparin) are usually the first treatment for a blood clot. They act quickly. However, they cannot be taken orally.

  • Heparin can cause a fall in a component of blood that stops bleeding and forms blood clots (platelets). You will be monitored with blood tests to be sure this does not occur.

  • Warfarin is an anticoagulant that can be swallowed (taken orally). It takes a few days to start working, so usually heparin or related medicines are used in combination. Once warfarin is working, heparin is usually stopped.

  • Less commonly, clot dissolving drugs (thrombolytics) are used to dissolve a DVT. They carry a high risk of bleeding, so they are used mainly in severe cases, where a life or limb is threatened.

  • Very rarely, a blood clot in the leg needs to be removed surgically.

  • If you are unable to take anticoagulants, your caregiver may arrange for you to have a filter placed in a main vein in your belly (abdomen). This filter prevents clots from traveling to your lungs.


  • Take all medicines prescribed by your caregiver. Follow the directions carefully.

  • Warfarin. Most people will continue taking warfarin after hospital discharge. Your caregiver will advise you on the length of treatment (usually 3–6 months, sometimes lifelong).

  • Too much and too little warfarin are both dangerous. Too much warfarin increases the risk of bleeding. Too little warfarin continues to allow the risk for blood clots. While taking warfarin, you will need to have regular blood tests to measure your blood clotting time. These blood tests usually include both the prothrombin time (PT) and international normalized ratio (INR) tests. The PT and INR results allow your caregiver to adjust your dose of warfarin. The dose can change for many reasons. It is critically important that you take warfarin exactly as prescribed, and that you have your PT and INR levels drawn exactly as directed.

  • Many foods, especially foods high in vitamin K can interfere with warfarin and affect the PT and INR results. Foods high in vitamin K include spinach, kale, broccoli, cabbage, collard and turnip greens, brussels sprouts, peas, cauliflower, seaweed, and parsley as well as beef and pork liver, green tea, and soybean oil. You should eat a consistent amount of foods high in vitamin K. Avoid major changes in your diet, or notify your caregiver before changing your diet. Arrange a visit with a dietitian to answer your questions.

  • Many medicines can interfere with warfarin and affect the PT and INR results. You must tell your caregiver about any and all medicines you take, this includes all vitamins and supplements. Be especially cautious with aspirin and anti-inflammatory medicines. Ask your caregiver before taking these. Do not take or discontinue any prescribed or over-the-counter medicine except on the advice of your caregiver or pharmacist.

  • Warfarin can have side effects, primarily excessive bruising or bleeding. You will need to hold pressure over cuts for longer than usual. Your caregiver or pharmacist will discuss other potential side effects.

  • Alcohol can change the body's ability to handle warfarin. It is best to avoid alcoholic drinks or consume only very small amounts while taking warfarin. Notify your caregiver if you change your alcohol intake.

  • Notify your dentist or other caregivers before procedures.

  • Activity. Ask your caregiver how soon you can go back to normal activities. It is important to stay active to prevent blood clots. If you are on anticoagulant medicine, avoid contact sports.

  • Exercise. It is very important to exercise. This is especially important while traveling, sitting or standing for long periods of time. Exercise your legs by walking or by pumping the muscles frequently. Take frequent walks.

  • Compression stockings. These are tight elastic stockings that apply pressure to the lower legs. This pressure can help keep the blood in the legs from clotting. You may need to wear compressions stockings at home to help prevent a DVT.

  • Smoking. If you smoke, quit. Ask your caregiver for help with quitting smoking.

  • Learn as much as you can about DVT. Knowing more about the condition should help you keep it from coming back.

  • Wear a medical alert bracelet or carry a medical alert card.


  • You notice a rapid heartbeat.

  • You feel weaker or more tired than usual.

  • You feel faint.

  • You notice increased bruising.

  • You feel your symptoms are not getting better in the time expected.

  • You believe you are having side effects of medicine.


  • You have chest pain.

  • You have trouble breathing.

  • You have new or increased swelling or pain in one leg.

  • You cough up blood.

  • You notice blood in vomit, in a bowel movement, or in urine.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.