Deep vein thrombosis is a serious but preventable medical condition in which blood clots occur, usually in veins in the lower leg, thigh, pelvis, and sometimes arms.
Deep vein thrombosis (DVT) is treatable, but it can have serious complications. For this reason, it is important to seek medical care if symptoms appear.
Pulmonary embolism (PE) is often associated with DVT. It usually happens when a part of a blood clot from a DVT breaks off from its original location in a vein and travels through the heart to the pulmonary arteries. This can result in damage to the lungs and other organs. It can be life-threatening.
DVT and PE can happen when the blood clot is in one of the deep veins, including those in the pelvis, thigh, or calf region.
Blood clots that form in veins closer to the skin’s surface, known as superficial venous thrombosis, typically do not result in a PE.
It is also possible to have a PE without DVT.
Anyone can develop DVT and PE. Many factors can contribute, but having multiple factors at once can increase the chance of having a blood clot.
The American Academy of Orthopaedic Surgeons (AAOS) note that the following common factors may increase the risk of DVT and PE:
- older age
- cancer or undergoing radiotherapy or chemotherapy for cancer
- injury to a vein from a fracture, muscle injury, or major surgery
- slow blood flow, especially in the lower extremities
- limited movement, due to bed rest, traveling, sitting for a long time, crossing the legs, paralysis, or other reasons
- having varicose veins or another existing condition
- high estrogen levels from birth control pills, hormone replacement therapy, or pregnancy
- having a personal or family history of DVT and PE or clotting disorders
- having a central venous catheter
- tobacco smoking
- having a broken hip or leg
- having experienced major surgery on the hip, knee, or leg, especially in the first 2 to 10 days after surgery
The Centers for Disease Control and Prevention (CDC) estimate that DVT, PE or both might affect up to 900,000 people in the United States each year.
DVT and PE are more likely to affect women of childbearing age than men of the same age.
After menopause, women have a lower risk for DVT and PE than men, but anyone can have DVT and PE.
For this reason, it is important to know the warning signs and symptoms.
Symptoms of DVT
Some people with DVT have no symptoms at all, but anyone who has symptoms and any of the above risk factors should seek medical advice as soon as possible.
- a feeling of constant cramping in the calf
- swelling, pain, and warmth in the extremities, especially on one side
- redness of the skin
- swollen or thickened blood vessels
Symptoms of PE
A PE can occur with or without symptoms of DVT.
It can be serious. If a person experiences any of the following, they should see a doctor immediately:
A doctor will start by asking the person about their symptoms, and they will do a physical examination. They may then order some imaging tests.
These usually are not overly invasive or uncomfortable.
A mathematical model can help doctors assess a person’s risk of DVT and PE using a range of chemical signs in the blood. It is often the first test a doctor will perform when trying to diagnose DVT.
A D-dimer test is a blood test that can determine if there might be any excess blood clotting in the body. Doctors will usually carry this out after a mathematical model.
If it is negative and you have a low risk for blood clots, the chance of having a DVT or PE is very low. No further testing would be necessary after a negative D-dimer result.
However, a positive test does not necessarily indicate a serious problem. This could refer to something as simple as blood clotting in a healing skin wound or bruise.
A VQ scan of the lungs can identify how well blood and oxygen are moving in the lungs. It involves the administration of a small amount of a radioactive substance.
However, if an individual requires further testing after a D-dimer test, doctors should use a VQ scan instead of a CT scan. The person’s exposure to radiation is lower.
A duplex ultrasound examination can detect blood clots in veins or other reasons for the vascular problem.
A spiral chest CT scan can check for blood clots in the arteries of the lungs, commonly done with an intravenous injection of contrast to better see the pulmonary arteries.
An MRI can evaluate the veins in the pelvis or both legs at the same time. This is less common than other tests for DVT and PE.
Venography involves injecting dye into a vein of an extremity and taking an x-ray to look for any blockages.
Blood tests can also find out if a person has a clotting disorder, of which several types exist. However, these tests are very expensive, and the results can take several days.
Normally, a doctor will only recommend them if:
- a person has had a DVT or PE, and there is concern about a clotting disorder
- the doctor wishes to screen the person for a clotting disorder because they have a family history of DVT or PE
It is very important to catch and treat DVT before a PE develops.
A person with DVT will usually need anticoagulants, or blood thinners, such as warfarin (Coumadin).
People who need to take anticoagulants should seek treatment from a specialized anticoagulant management service rather than their family doctor or a primary care physician.
Anticoagulants achieve two effects:
- they stop the blood from clotting too much
- they stop existing blood clots from enlarging
However, anticoagulants do not break up existing blood clots. They can only interrupt the clotting process so that the body can break down the clots through its normal mechanisms.
A doctor may give an anticoagulant medication as pills or as an injection.
Most people will need to use anticoagulant medication for at least 3 months, but each person is different.
Factors that affect treatment, include:
- pregnancy in women
- short-term versus long-term blood clot risks
- having a history of blood clots
- other illnesses the person may have
Inferior vena cava (IVC) filter
Some people cannot use blood thinners because they have a high risk of bleeding.
They may need an inferior vena cava (IVC) filter.
The doctor inserts this filter is into a large vein in the abdomen called the inferior vena cava. There, it can catch blood clots before they can cause PE.
However, the filter does not stop new blood clots from forming. Sometimes clots can pass around the filter through smaller veins or form on the filter, break off, and still reach the lungs. The IVC filter may also be used for some patients in addition to anticoagulant medication therapy.
In severe cases of DVT, a vascular surgeon has two options:
- They can access the vein where the clot is and either remove the clot in a procedure known as thrombectomy.
- They can use a TPA thrombolytic medication, also called a “clot buster,” at the site of the DVT to break it down.
Treatment for PE
Treatment for PE also usually involves anticoagulant therapy for at least 3 months or more.
If a PE is life-threatening, the doctor may administer a thrombolytic medication.
This breaks down the blood clot, but it can be dangerous, as it may lead to bleeding in other parts of the body, such as the brain and the gastrointestinal tract.
Doctors must decide on a case-by-case basis about giving this type of medication.
In rare cases, a surgeon may need to remove the blood clot from the lungs in a procedure known as an embolectomy. This is a risky procedure. The doctor usually would only use it as a last resort in a very severe case.
People can reduce their risk of developing DVT and PE by:
- staying healthy
- managing their weight
- avoiding a sedentary lifestyle
- telling their doctor if there is a family history of blood clotting disorders
Tips for traveling
Some simple rules can help to prevent DVT and blood clots, especially when traveling.
- taking activity breaks if sitting for a long period of time, for example, over 4 hours
- moving as much as possible, even when seated
- doing seated exercises, such as leg raises, tightening and loosening leg muscles, and doing heel and toe lifts
- wearing compression stockings, for people who have a high risk of venous thromboembolism (VTE)
- drinking plenty of fluid
- following a healthful, balanced diet
When traveling on an airplane, people can walk up and down the aisle every half an hour.
People with a family or personal history of blood clots should pay attention to signs and symptoms that could indicate DVT or PE.
It is important to keep moving and avoid being still for long periods of time, to lessen the chances of DVT and PE occurring.
Those who need anticoagulant medication should follow their doctor’s instructions.
Do you recommend any particular diet for someone who is at risk of DVT?
People should try to make well-balanced and healthy dietary choices, especially if they have a risk of DVT.
This includes healthy portion sizes and a good balance of lean meats or fish, vegetables, fruits, and whole grains
This can help you to maintain a healthier weight and provide energy for you to be more physically active.
Combined with an active lifestyle, a healthy diet can help you to avoid becoming sedentary, and this will lower your risk for DVT and subsequent PE.
Making healthy choices in your diet will also reduce your risk for other chronic medical ailments, such as obesity, diabetes mellitus, high blood pressure, high cholesterol, and heart disease, and you’ll likely feel better in the long-run.Stacy Sampson, DO Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.