Deep Vein Thrombosis

everything you need to know about DVT

Venous thrombosis is a condition in which a blood clot (thrombus) forms in a vein. This clot can limit blood flow through the vein, causing swelling and pain on the area distal to the clot. Most commonly, venous thrombosis occurs in the “deep veins” in the legs, thighs, or pelvis. This is called a deep vein thrombosis, or DVT.

DVT is the most common type of venous thrombosis. However, a clot can form anywhere in the venous system. If a part or all of the blood clot in the vein breaks off from the site where it is formed, it can travel through the venous system; this is called an embolus. If the embolus lodges in the lung, it is called pulmonary embolism (PE), a serious condition that leads to over 50K deaths a year in the United States.

In this video I will discuss the risk factors, signs and symptoms, diagnostic process, and even the treatment of a DVT.


If a person is found to have a DVT and there is no known medical condition or recent surgery that could have caused the DVT, it is possible that an inherited / congenital condition is to blame. This is especially true in peopl who have a family history of DVT or PE. In these cases, testing for an inherited thrombophilia (a genetic problem that causes the blood to clot more easily than normal) may be recommended.

Medical conditions or medications 

— Some medical conditions and medications increase your risk of developing a blood clot:


●Immobilization (eg, due to hospitalization, recovery from injury, bedrest, or paralysis)

●Previous DVT or PE

●Increased age



●Certain medications (eg, birth control pills, hormone replacement therapy, tamoxifen, thalidomide, erythropoietin).

The risk of a blood clot is further increased in people who use one of these medications and also have other risk factors.


●Heart failure

●Kidney problems, such as nephrotic syndrome

Surgery and related conditions 

— Surgical procedures, especially those involving the hip, pelvis, or knee, increase a person’s risk of developing a blood clot. During the recovery period, prolonged inactivity can also increase the risk of developing a blood clot.

People diagnosed with a venous thromboembolism are occasionally found to have an inherited thrombophilia. Examples of inherited thrombophilia include factor V Leiden; the prothrombin gene mutation; and deficiencies of antithrombin, protein C, or protein S.

Acquired thrombophilia — Some types of thrombophilia are not inherited, but can still increase a person’s risk of developing a blood clot. Examples include:

●Certain disorders of the blood, such as polycythemia vera (too many red cells) or essential thrombocythemia (too many platelets)

●Antiphospholipid antibodies (antibodies in the blood that can affect the clotting process)

Elevated clotting factors — Having an increased level of one or more factors involved in blood clotting, such as factor VIII, increases the risk of a blood clot.


 Classic symptoms of DVT include swelling, pain, warmth, and redness in the involved leg.

Superficial phlebitis — Superficial phlebitis (SP) causes pain, tenderness, firmness, and/or redness in a vein due to inflammation, infection, and/or a blood clot (thrombus). It is most commonly seen in the inner part of the lower legs. SP differs from a deep vein thrombosis because the veins that are affected are near the surface of the skin. Superficial phlebitis is NOT a DVT, but…BUT… in up to 15% of cases if you have SP you can also have a DVT.


— If your history, symptoms, and physical exam suggest a DVT, you will get tests to confirm the diagnosis. Tests may include (1) a blood test called D-dimer and (2) compression ultrasonography of the legs and/or (3) other imaging tests.


— D-dimer is a substance in the blood that is often increased in people with DVT or PE. If the D-dimer test is negative and you have a low risk of DVT or PE based on your history and physical examination, DVT or PE are unlikely and further diagnostic testing may not be needed.

Compression ultrasonography 

— Compression ultrasonography uses sound waves to generate pictures of the structures inside the leg. For this type of exam, you lie on your back and then stomach as an ultrasound wand is applied to the leg. In most circumstances, compression ultrasonography is the test of choice for patients with suspected DVT.

Other imaging tests 

— Although no longer used widely used for diagnosis, in some cases (for example, if it is not possible to perform ultrasonography for some reason) another imaging test may done. These include MRI (which uses a strong magnet to produce detailed pictures of the inside of the body), and computed tomography (CT) scan.

Finding the cause of a blood clot 

— After confirming that DVT or PE is present, the healthcare provider will want to know what caused it. In many cases, there are obvious risk factors such as recent surgery or immobility. In other cases, the clinician may test for the presence of an inherited form of thrombophilia or for another medical condition associated with an increased risk for venous thrombosis (such as cancer).

People with some acquired or inherited abnormalities may require additional treatment or prevention measures to reduce the risk of another thrombosis. Some experts recommend that the family members of a person with an inherited thrombophilia be screened for the inherited condition if this information would affect their care as well.


— In treating DVT, the main goal is to prevent a PE. Other goals of treatment include preventing the clot from becoming larger, preventing new blood clots from forming, and preventing long-term complications.

The treatment of DVT and pulmonary embolism (PE) are similar. In both cases, the primary approach is anticoagulation. Other available treatments, which may be used in specific situations, include thrombolytic therapy or placing a filter in a major blood vessel (the inferior vena cava).


— Anticoagulants are medications that are commonly called “blood thinners.” They do not actually dissolve the clot, but rather help to prevent new blood clots from forming. There are several different medications that might be given

●Direct oral anticoagulants – These are available in pill form; Xarelto, EliquiS, Pradaxa.

●Low molecular weight (LMW) heparin, which is given as an injection under the skin – Lovenox, and Fragmin.

●Unfractionated heparin, which is given into a vein (intravenously) or as an injection under the skin – This may be the preferred choice in certain circumstances, such as if a person has severe kidney failure.

Initial anticoagulation usually consists of 5 to 10 days of treatment LMW heparin, or unfractionated heparin. After that, long-term anticoagulation is continued for 3 to 12 months.

The choice of anticoagulant depends upon multiple factors, including your preference, your doctor’s recommendation based on your situation and medical history, and cost considerations. Some of these medications are super expensive, so if money is an issue make sure you visit the manufacturer’s website which usually provide 1 month of FREE therapy.

Duration of treatment — Anticoagulation is recommended for a MINIMUM of three months in a patient with DVT.

●If you had a reversible risk factor contributing to your DVT, such as trauma, surgery, or being confined to bed for a prolonged period, you will likely be treated with anticoagulation for only three months or until the risk factor is resolved.

●Expert groups suggest that people who develop a DVT but do not have a known risk factor may need treatment with an anticoagulant for an indefinite period of time. However, if this is your situation, you should discuss the pros and cons with your doctor after three months of treatment. If the decision is made to continue anticoagulation, your doctor will continue to reassess on a regular basis. Some people prefer to continue the anticoagulant, which may carry an increased risk of bleeding, while others prefer to stop the anticoagulant at some point, which may carry an increased risk for repeat thrombosis.

● For people with two or more episodes of venous thrombosis or if a risk factor for clotting persists.

Walking during DVT treatment — It used to be that if we diagnosed you with a DVT we put you in the hospital under bed rest. As we were afraid that moving around would dislodge the clot and turn it into an embolism. However, once an anticoagulant has been started and symptoms (such as pain and swelling) are under control, you are strongly encouraged to get up and walk around periodically. Studies show that there is no increased risk of complications (eg, pulmonary embolus) in people who get up and walk, and walking may in fact help you feel better faster.

Thrombolytic therapy — In some severe life-threatening cases, a healthcare provider will recommend an intravenous medicine to dissolve blood clots (ie, a “clot-busting” medication). This is called thrombolytic therapy. This therapy is reserved for people who have serious complications related to DVT or PE, and who have a low risk of serious bleeding as a side effect of the therapy. The response to thrombolytic therapy is best when there is a short time between the diagnosis of DVT/PE and the start of thrombolytic therapy.

Inferior vena cava filter — An inferior vena cava (IVC) filter is an umbrella-type device that blocks clots traveling in the bloodstream from reaching your heart. It is placed in the inferior vena cava (the large vein leading from the lower body to the heart).

An IVC filter may be recommended in people with venous thromboembolism who cannot use anticoagulants because of a very high bleeding risk. However, in the long term, IVC filters can actually increase the risk of developing blood clots.


During hospitalization — Some people who are in the hospital, either for surgery (especially bone or joint surgery and cancer surgery) or because of a serious medical illness, may be given anticoagulants to decrease the risk of blood clots. Anticoagulants may also be given to women at high risk for venous thrombosis during and after pregnancy.

In people who are hospitalized and have a moderate to low risk of blood clots, other preventive measures may be used. For example, some people are fitted with inflatable compression devices after surgery. These devices are worn around the legs during and immediately after surgery and periodically fill with air. These devices apply gentle pressure to improve circulation and help prevent clots. Another alternative is the use of compression stockings may also be recommended.

In all cases, walking as soon as possible after surgery can decrease the risk of a blood clot; it can also decrease the risk of chronic swelling in the legs from your DVT (also known as “post-thrombotic syndrome”).

Extended travel — Prolonged travel (for example, taking a long airplane flight or car ride…and by prolonged we mean 4 hours or more) appears to increase the risk of developing blood clots.


Risk of developing another clot — People being treated for venous thrombosis are at an increased risk for developing another blood clot, although this risk is significantly smaller when an anticoagulant is used. Watch for new leg pain, swelling, and/or redness; if any of these symptoms occur, call your doctor or seek medical attention as soon as possible.

Other symptoms may indicate that a clot in the leg has broken off and traveled to the lung, causing a pulmonary embolism. These may include:

●New chest pain with difficulty breathing

●A rapid heart rate and/or a feeling of passing out

A PE can be life-threatening and requires immediate attention. If you have the above symptoms, call for help right away.

Bleeding risk — Anticoagulants such as heparin and warfarin can have serious side effects and should be taken exactly as directed. If you forget or miss a dose, call your healthcare provider or clinic for advice. Do not try to take an extra dose or change the dose yourself unless your doctor specifically tells you to. If you take warfarin, there are many other things you need to be aware of as well as its effect on anti-coagulation can be affected greatly by your diet and interactions with other medications.

You are more likely to bleed easily while taking anticoagulants. Bleeding may develop in many areas, such as the nose or gums, excessive menstrual bleeding in women, bleeding in the urine or feces, bleeding or excessive bruising in the skin, or vomiting material that is bright red or looks like coffee grounds.

Bleeding inside the body can cause you to feel faint, or have pain in the back or abdomen. Call your healthcare provider right away if you have these symptoms. It’s also important to call immediately if you have an injury that could cause internal bleeding, such as a fall or a car accident, even those that seem minor. I myself have seen many patients with significant brain bruises/hematomas with minor head injuries or even falls without direct head trauma.

Some simple modifications can reduce your risk of bleeding. For example, you can:

●Use a soft bristle toothbrush

●Shave with an electric razor rather than a blade

●Use caution when handling sharp objects (shaving razors, knives)

●Avoid activities that could result in injury (eg, contact sports)

●Use appropriate safety equipment (eg, helmets, padding) during physical activity

●Avoid aspirin or other non-steroidal antiinflammatory agents (NSAIDS) unless your healthcare provider tells you to take them. If you need to take something for pain, other non-prescription pain medications, such as acetaminophen, may be a safe alternative.

Wear an alert tag — While you are taking anticoagulants, wear a medical bracelet, necklace, or similar alert tag that includes the name of your anticoagulant at all times. If you end up needing treatment and are unable to explain your condition, the tag will alert responders that you are on an anticoagulant and at risk of excessive bleeding.

The alert tag should list your medical conditions as well as the name and phone number of an emergency contact. One device, Medic Alert, provides a toll-free number that emergency medical workers can call to find out your medical history, list of medications, family emergency contact numbers, and healthcare provider names and numbers.

  • Dr. Carlo Oller (emergency physician with has put together more than 1800 FREE patient education videos which can be found at
  • Please contact Dr. Carlo Oller at if you would like to use his videos in your own website, or educational materials. Or if you would like some more information or education on a title NOT available at this time.

Leave a Reply