A pulmonary embolism occurs when a blood clot that has developed elsewhere in your body (often in your arm or leg) travels through your bloodstream to your lungs and becomes stuck in a blood vessel.
Even though a pulmonary embolism can sometimes dissolve on its own, it can also be a life-threatening condition that can result in damage to your heart or even death.
There are many tests that can be used to diagnose and analyze pulmonary embolism, including blood tests, CT scans, ultrasounds, and MRI testing. Read on to learn more about the blood tests used to diagnose pulmonary embolism and what you can expect.
Types of blood tests for pulmonary embolism
Your doctor will order a D-dimer blood test to help diagnose or rule out the presence of a pulmonary embolism. The D-dimer test measures the levels of a substance that is produced in your bloodstream when a blood clot breaks down.
If your doctor thinks that the probability that you have a pulmonary embolism is high based off their clinical assessment, a D-dimer test might not be performed.
If you’ve been diagnosed with pulmonary embolism, your doctor may order a troponin test to help evaluate if any injury to your heart has occurred. Troponin is a protein that’s released into your bloodstream when there’s been damage to your heart.
Like the troponin blood test, your doctor may order a BNP blood test if you’ve been diagnosed with a pulmonary embolism. This test is normally ordered to evaluate the seriousness of heart failure. BNP and related compounds are released into the bloodstream when the heart is working too hard to pump blood. This can happen in pulmonary embolism due to the blockage of blood vessels.
How is the test done?
In order to collect the sample for the D-dimer, troponin, and BNP blood tests, a blood sample will be drawn from a vein in your arm.
What do the results mean?
If the results of the D-dimer blood test fall into the normal or negative range and you don’t have many risk factors, you likely don’t have a pulmonary embolism. However, if the results are high or positive, it indicates that there is significant clot formation and degradation occurring in your body.
A positive D-dimer result doesn’t indicate where the clot is located in your body. Your doctor will have to order further tests to obtain that information.
Additionally, there are other factors that can cause your D-dimer result to be high. These include:
- recent surgery or trauma
- heart attack
- current or recent infection
- liver disease
High levels of troponin in your blood, particularly in a series of troponin blood tests performed over several hours, indicates that there has probably been some damage to the heart.
Because troponin release is specific to injury of your heart muscles, this test can’t detect injury to other muscles in your body, such as skeletal muscles.
Other conditions that can lead to elevated troponin include:
- heart attack
- stable or unstable angina
- congestive heart failure
- heart inflammation
- kidney disease
- current or recent infection
- tachycardia and tachyarrhythmias
The level of BNP present in the blood is related to the severity of the heart failure, with higher levels indicating a poorer outlook.
BNP levels can also be increased in the blood due to the following factors:
- increased age
- kidney disease
- dysfunction of the left or right ventricle of the heart
How is this treated?
Pulmonary embolism can be diagnosed using a high D-dimer result combined with confirmatory results from other tests, such as ultrasounds and CT scans. Once it’s diagnosed, you’ll typically have treatment in a hospital so that your condition can be monitored.
Treatment options include:
- Anticoagulants, such as warfarin or heparin. These medications are also referred to as blood thinners. They lower your blood’s ability to clot and thus prevent further clots from forming.
- Thrombolytics. This medication can quickly break up large blood clots. However, it can cause serious sudden bleeding, so it’s only used in a life-threatening situation.
- Surgical removal. Your doctor may recommend surgery to remove the clot.
- Vena cava filter. A filter may be placed into a large vein in your body called the vena cava. This filter will help to trap clots before they can become lodged in your lungs.
- Use of compression stockings. These are typically knee-high stockings that help with the blood flow in your legs by preventing blood from pooling.
Outlook and prevention
The length and type of treatment is dependent on the severity of your pulmonary embolism. In most cases, your treatment will consist of anticoagulants. Your doctor will schedule monitoring appointments during your recovery and may request additional blood tests to monitor your condition and your anticoagulant therapy.
As always, it’s very important to follow your doctor’s instructions regarding your recovery and medications.
Additionally, you can make lifestyle changes to help prevent a pulmonary embolism from occurring again. In order to prevent pulmonary embolism, you must work to prevent deep vein thrombosis (DVT). DVT occurs when a clot forms in one of your body’s large blood vessels, typically in your arm or leg. It’s this clot that can travel throughout your bloodstream and become lodged in the blood vessels of your lungs.
Following is a list of pulmonary embolism prevention tips:
- Exercise the muscles of your lower legs. If you spend a lot of time in a seated position, try to occasionally get up and walk around for a few minutes. This is particularly important when traveling long distances via plane or car.
- Make sure that you drink plenty of water while avoiding alcohol and caffeine.
- Avoid clothing that is tight-fitting and constrictive to blood flow.
- Avoid crossing your legs.
- Avoid smoking.
- Try to lose weight if you’re overweight.
- If you’ve been bedridden due to surgery or illness, be sure to get up and start moving around as soon as you’re able.
- Be aware of the symptoms of DVT. If you’re experiencing DVT symptoms, you should notify your doctor immediately. Symptoms include:
- swelling of the arm or leg
- increased warmth in the arm or leg
- leg pain that’s only present when standing or walking
- redness of the skin
- enlarged veins in the affected arm or leg