Pulmonary Embolism Diagnosis: The 3-Step Process

Table of ContentsView AllTable of ContentsPulmonary Embolism DiagnosisDiagnosis In Unstable CasesDifferential DiagnosisFrequently Asked QuestionsNext in Pulmonary Embolism GuidePulmonary Embolism Treatment and Management

Table of ContentsView All

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Table of Contents

Pulmonary Embolism Diagnosis

Diagnosis In Unstable Cases

Differential Diagnosis

Frequently Asked Questions

Next in Pulmonary Embolism Guide

Pulmonary embolismis a common medical disorder that can have serious consequences. Appropriatetreatment, delivered expeditiously, is important for optimizing the chances of a full recovery. Giving the appropriate treatment requires making the correct diagnosis as quickly as possible.

Over time, experts have developed a three-step approach designed to rapidly rule out or diagnose a pulmonary embolus without exposure to unnecessary testing.These steps include:

This article will discuss those diagnostic steps in detail, as well as what healthcare providers do in emergencies, when there isn’t time for a full workup.

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pulmonary embolus diagnosis

Making a quick and accurate pulmonary embolism diagnosis can be tricky. The most definitive tests for pulmonary embolus can be time-consuming, expensive, and entail at least some clinical risks. Healthcare providers tend to weigh the risks and benefits before deciding what kind of testing is appropriate in a given circumstance.

If your healthcare providersuspects you may have had a pulmonary embolus, you can expect them to use this three-step diagnostic approach:

Step One

In step one, the healthcare provider quickly assesses you for warning signs that a pulmonary embolus has occurred. They will take yoursymptomsinto account and consider how you match up with clinical pulmonary embolism criteria.

Several scoring systems have been devised for estimating the probability of a pulmonary embolus. The system used most often is theWells scoring system, which takes into account whether:

Point scores are assigned to each of these seven factors and an overall Wells score is computed.

With theWellsscore in hand, a healthcare provider can determine whether the probability of a pulmonary embolus is low, intermediate, or high.

Pulmonary Embolus Rule-Out Criteria (PERC)

If it turns out there is only a low probability of pulmonary embolus based on this clinical assessment, the healthcare provider may also apply an additional scoring system: the PERC system.

The PERC system can determine whether the probability of a pulmonary embolus is so low that further testing should be stopped altogether. It consists of eight pulmonary embolism criteria:

If all eight criteria of the PERC score are present, no further testing for pulmonary embolus is recommended since the risk associated with additional testing will substantially outweigh the risk of missing a pulmonary embolus.

Step Two

If the probability of a pulmonary embolus in step one is determined to be intermediate, or if the clinical probability of pulmonary embolus is low but the PERC criteria have not been met, the next step is to obtain a D-dimer blood test.

The D-dimer test measures whether there has been an abnormal level of clotting activity in the bloodstream, such as would certainly be present if a person has had a deep vein thrombosis or pulmonary embolus.

If the clinical probability of PE is low or intermediate and the D-dimer test is negative, a pulmonary embolus generally can be ruled out and the healthcare provider will move on to consider other potential causes for symptoms.

A D-dimer test can be used only to rule out a pulmonary embolus, not to make the diagnosis. So if the D-dimer test is positive (or if a person’s clinical probability of a pulmonary embolus was deemed to be high in step one), it is time for step three.

Step Three

Step three involves a diagnostic imaging study. Generally, one of three kinds of tests will be used.

CT Scan

A CT scan is accurate more 90% of the time in detecting a pulmonary embolus and is considered to be the test of choice if imaging is required to make the diagnosis.

V/Q Scan

Pulmonary Angiogram

For a pulmonary angiogram, dye is injected through a catheter placed into the pulmonary artery so that blood clots can be visualized on an X-ray.

This invasive test may still be required on occasion if a CT scan or a V/Q scan cannot be used or the results from these tests are inconclusive.

Blood Clots After Surgery

A pulmonary embolus may cause immediate cardiovascular collapse. In fact, a pulmonary embolus often turns out to be the cause of sudden death in younger people.

If an individual has severe cardiovascular instability and a pulmonary embolus seems likely to be the cause, an organized three-step diagnostic plan is not feasible. For them,treatmentlikely will be administered immediately, along with other resuscitative efforts, before a definitive diagnosis of pulmonary embolus can be made.

Chronic Thromboembolic Pulmonary Hypertension (CTEPH): What Happens?

In diagnosing a pulmonary embolus, it is important to rule out other medical diagnoses whose symptoms can be similar to those of a pulmonary embolus. Conditions that need to be considered (that is, the differential diagnosis) often includeheart attacks,heart failure,pericarditis,cardiac tamponade, pneumonia, andpneumothorax.

Theelectrocardiograms, chest X-rays, andechocardiogramsthat are often obtained during routine clinical evaluations for suspected heart or lung disorders are usually enough to rule out these other conditions.

Even if one of these other diagnoses is made, it does not necessarily mean that a pulmonary embolus is ruled out, because a person may have two conditions at the same time—and many cardiovascular diseases increase the risk of pulmonary embolus. So if there is still reason to suspect a possible pulmonary embolus after another diagnosis is made, it is important to take the additional steps necessary to complete diagnostic testing.

In the some cases, apulmonary infarctionis diagnosed as an additional finding when looking for a pulmonary embolus.

Frequently Asked QuestionsUsually, a special type of X-ray is done to confirm whether you have a pulmonary embolism. Known as a computed tomographic pulmonary angiography (CTPA), this scan requiresdye to be injected into a veinin order to capture an image of the blood vessels in the lungs.AD-dimer testis a blood test that can show if a blood clot has broken down.If you’re diagnosed with a pulmonary embolism, other blood tests will be ordered to determine if you’ve suffered heart damage from the embolism.Other conditions can have similar symptoms. These include heart attack, heart failure, pericarditis, pneumonia, and hyperventilation.Because your healthcare provider needs to rule out these other problems and because pulmonary embolism can be hard to diagnose, you may need to undergo several tests before the diagnosis is confirmed.Warning signs of a pulmonary embolism include shortness of breath, chest pain, lightheadedness, irregular heartbeat or palpitations, coughing and/or coughing up blood, sweating, a feeling of anxiety, and low blood pressure.About 10% to 25% of people with pulmonary embolism have a normal ECG. However, an ECG may still be used to assess for PE because it can confirm if certain PE warning signs are present, such as sinus tachycardia, right bundle branch block (RBBB), atrial fibrillation, and more.

Usually, a special type of X-ray is done to confirm whether you have a pulmonary embolism. Known as a computed tomographic pulmonary angiography (CTPA), this scan requiresdye to be injected into a veinin order to capture an image of the blood vessels in the lungs.

AD-dimer testis a blood test that can show if a blood clot has broken down.If you’re diagnosed with a pulmonary embolism, other blood tests will be ordered to determine if you’ve suffered heart damage from the embolism.

Other conditions can have similar symptoms. These include heart attack, heart failure, pericarditis, pneumonia, and hyperventilation.Because your healthcare provider needs to rule out these other problems and because pulmonary embolism can be hard to diagnose, you may need to undergo several tests before the diagnosis is confirmed.

Warning signs of a pulmonary embolism include shortness of breath, chest pain, lightheadedness, irregular heartbeat or palpitations, coughing and/or coughing up blood, sweating, a feeling of anxiety, and low blood pressure.

About 10% to 25% of people with pulmonary embolism have a normal ECG. However, an ECG may still be used to assess for PE because it can confirm if certain PE warning signs are present, such as sinus tachycardia, right bundle branch block (RBBB), atrial fibrillation, and more.

Pulmonary Embolism Treatment and Management

10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Raja AS, Greenberg JO, Qaseem A, et al.Evaluation of patients with suspected acute pulmonary embolism: Best practice advice from the clinical guidelines committee of the american college of physicians.Ann Intern Med.2015;163:701. doi:10.7326/M14-1772Tarbox AK, Swaroop M.Pulmonary embolism.Int J Crit Illn Inj Sci. 2013;3(1):69-72. doi:10.4103/2229-5151.109427Singh B, Mommer SK, Erwin PJ, et al.Pulmonary embolism rule-out criteria (perc) in pulmonary embolism—revisited: A systematic review and meta-analysis.Emerg Med.J 2013; 30:701. doi:10.1136/emermed-2012-201730Moore AJE, Wachsmann J, Chamarthy MR, et la.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018 Jun; 8(3): 225–243. doi:10.21037/cdt.2017.12.01Moore AJE, Wachsmann J, Chamarthy MR, et al.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018;8(3):225-243. doi:10.21037/cdt.2017.12.01Centers for Disease Control and Prevention.Diagnosis and treatment of venous thromboembolism.Weitz JI, Fredenburgh JC, Eikelboom JW.A test in context: D-dimer.J Am Coll Cardiol. 2017; 70:2411. doi:10.1016/j.jacc.2017.09.024.Stein CE, Keijsers CJPW, Bootsma JEM, Schouten HJ.Missed diagnosis of pulmonary embolism with age-adjusted d-dimer cut-off value.Age Ageing. 2016;45(6):910-911. doi:10.1093/ageing/afw132Johns Hopkins Medicine.Pulmonary embolism.Boey E, Teo SG, Poh KK.Electrocardiographic findings in pulmonary embolism.Singapore Med J. 2015 Oct;56(10):533-537. doi:10.11622/smedj.2015147Additional ReadingKlok FA, Kruisman E, Spaan J, et al.Comparison of the revised geneva score with the wells rule for assessing clinical probability of pulmonary embolism.J Thromb Haemost.2008; 6:40. doi:10.1111/j.1538-7836.2007.02820.xSmith SB, Geske JB, Maguire JM, et al.Early anticoagulation is associated with reduced mortality for acute pulmonary embolism.Chest.2010; 137:1382. doi:10.1378/chest.09-0959

10 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Raja AS, Greenberg JO, Qaseem A, et al.Evaluation of patients with suspected acute pulmonary embolism: Best practice advice from the clinical guidelines committee of the american college of physicians.Ann Intern Med.2015;163:701. doi:10.7326/M14-1772Tarbox AK, Swaroop M.Pulmonary embolism.Int J Crit Illn Inj Sci. 2013;3(1):69-72. doi:10.4103/2229-5151.109427Singh B, Mommer SK, Erwin PJ, et al.Pulmonary embolism rule-out criteria (perc) in pulmonary embolism—revisited: A systematic review and meta-analysis.Emerg Med.J 2013; 30:701. doi:10.1136/emermed-2012-201730Moore AJE, Wachsmann J, Chamarthy MR, et la.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018 Jun; 8(3): 225–243. doi:10.21037/cdt.2017.12.01Moore AJE, Wachsmann J, Chamarthy MR, et al.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018;8(3):225-243. doi:10.21037/cdt.2017.12.01Centers for Disease Control and Prevention.Diagnosis and treatment of venous thromboembolism.Weitz JI, Fredenburgh JC, Eikelboom JW.A test in context: D-dimer.J Am Coll Cardiol. 2017; 70:2411. doi:10.1016/j.jacc.2017.09.024.Stein CE, Keijsers CJPW, Bootsma JEM, Schouten HJ.Missed diagnosis of pulmonary embolism with age-adjusted d-dimer cut-off value.Age Ageing. 2016;45(6):910-911. doi:10.1093/ageing/afw132Johns Hopkins Medicine.Pulmonary embolism.Boey E, Teo SG, Poh KK.Electrocardiographic findings in pulmonary embolism.Singapore Med J. 2015 Oct;56(10):533-537. doi:10.11622/smedj.2015147Additional ReadingKlok FA, Kruisman E, Spaan J, et al.Comparison of the revised geneva score with the wells rule for assessing clinical probability of pulmonary embolism.J Thromb Haemost.2008; 6:40. doi:10.1111/j.1538-7836.2007.02820.xSmith SB, Geske JB, Maguire JM, et al.Early anticoagulation is associated with reduced mortality for acute pulmonary embolism.Chest.2010; 137:1382. doi:10.1378/chest.09-0959

Raja AS, Greenberg JO, Qaseem A, et al.Evaluation of patients with suspected acute pulmonary embolism: Best practice advice from the clinical guidelines committee of the american college of physicians.Ann Intern Med.2015;163:701. doi:10.7326/M14-1772Tarbox AK, Swaroop M.Pulmonary embolism.Int J Crit Illn Inj Sci. 2013;3(1):69-72. doi:10.4103/2229-5151.109427Singh B, Mommer SK, Erwin PJ, et al.Pulmonary embolism rule-out criteria (perc) in pulmonary embolism—revisited: A systematic review and meta-analysis.Emerg Med.J 2013; 30:701. doi:10.1136/emermed-2012-201730Moore AJE, Wachsmann J, Chamarthy MR, et la.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018 Jun; 8(3): 225–243. doi:10.21037/cdt.2017.12.01Moore AJE, Wachsmann J, Chamarthy MR, et al.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018;8(3):225-243. doi:10.21037/cdt.2017.12.01Centers for Disease Control and Prevention.Diagnosis and treatment of venous thromboembolism.Weitz JI, Fredenburgh JC, Eikelboom JW.A test in context: D-dimer.J Am Coll Cardiol. 2017; 70:2411. doi:10.1016/j.jacc.2017.09.024.Stein CE, Keijsers CJPW, Bootsma JEM, Schouten HJ.Missed diagnosis of pulmonary embolism with age-adjusted d-dimer cut-off value.Age Ageing. 2016;45(6):910-911. doi:10.1093/ageing/afw132Johns Hopkins Medicine.Pulmonary embolism.Boey E, Teo SG, Poh KK.Electrocardiographic findings in pulmonary embolism.Singapore Med J. 2015 Oct;56(10):533-537. doi:10.11622/smedj.2015147

Tarbox AK, Swaroop M.Pulmonary embolism.Int J Crit Illn Inj Sci. 2013;3(1):69-72. doi:10.4103/2229-5151.109427

Singh B, Mommer SK, Erwin PJ, et al.Pulmonary embolism rule-out criteria (perc) in pulmonary embolism—revisited: A systematic review and meta-analysis.Emerg Med.J 2013; 30:701. doi:10.1136/emermed-2012-201730

Moore AJE, Wachsmann J, Chamarthy MR, et la.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018 Jun; 8(3): 225–243. doi:10.21037/cdt.2017.12.01

Moore AJE, Wachsmann J, Chamarthy MR, et al.Imaging of acute pulmonary embolism: An update.Cardiovasc Diagn Ther. 2018;8(3):225-243. doi:10.21037/cdt.2017.12.01

Centers for Disease Control and Prevention.Diagnosis and treatment of venous thromboembolism.

Weitz JI, Fredenburgh JC, Eikelboom JW.A test in context: D-dimer.J Am Coll Cardiol. 2017; 70:2411. doi:10.1016/j.jacc.2017.09.024.

Stein CE, Keijsers CJPW, Bootsma JEM, Schouten HJ.Missed diagnosis of pulmonary embolism with age-adjusted d-dimer cut-off value.Age Ageing. 2016;45(6):910-911. doi:10.1093/ageing/afw132

Johns Hopkins Medicine.Pulmonary embolism.

Boey E, Teo SG, Poh KK.Electrocardiographic findings in pulmonary embolism.Singapore Med J. 2015 Oct;56(10):533-537. doi:10.11622/smedj.2015147

Klok FA, Kruisman E, Spaan J, et al.Comparison of the revised geneva score with the wells rule for assessing clinical probability of pulmonary embolism.J Thromb Haemost.2008; 6:40. doi:10.1111/j.1538-7836.2007.02820.xSmith SB, Geske JB, Maguire JM, et al.Early anticoagulation is associated with reduced mortality for acute pulmonary embolism.Chest.2010; 137:1382. doi:10.1378/chest.09-0959

Smith SB, Geske JB, Maguire JM, et al.Early anticoagulation is associated with reduced mortality for acute pulmonary embolism.Chest.2010; 137:1382. doi:10.1378/chest.09-0959

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