D Dimer and Pulmonary Embolism

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The causes of pulmonary embolism are a variety of symptomatic and other factors including heredity. Age, medical illness, pregnancy, drug abuse, malignancy, trauma, major surgery, and reduced mobility are others. The list is extensive and a treating physician should be consulted for patient-specific risks.

Risk Factors

Research has broken down the risk factors into various categories including race, age and gender. By race, African Americans are at the highest risk for pulmonary embolism, with Pacific Islanders/Asians/American Indians have a decidedly low risk factor.

By age, the risk increase with age. By gender, the risk is about evenly split, though women have a lower risk for recurrence.

Signs and Symptoms

Any chest symptoms should be thoroughly checked out by the treating physician, including as a means of ruling out pulmonary embolism. Studies show that in those patients with pulmonary embolism, the following symptoms were reported (in order of frequency of report):

  • Tachypnea
  • Rales
  • Accentuated second heart sound
  • Tachycardia
  • Fever
  • Diaphoresis
  • S3o or S4 gallop
  • Thrombophlebitis signs and symptoms
  • Edema in lower extremities
  • Cardiac murmur
  • Cyanosis

D Dimer and Pulmonary Embolism Diagnosis

Studies have shown that massive pulmonary embolisms affect approximately 4.5 percent of patients with pulmonary embolism, while the other approximate 95.5 percent had nonmassive pulmonary embolism. D dimer testing is one method for catching pulmonary embolism in patients and thereby helping to save lives.

A d dimer test will be ordered when certain signs and symptoms are present. In the test results, a positive d dimer means there is a presence of high fibrin degradation. This indicates clot formulation of a significant level. The d dimer test does not indicate the cause or reveal the location.


Pulmonary Embolism. National Heart, Lung and Blood Institute. National Institutes of Health. U.S. National Library of Medicine. https://www.nlm.nih.gov/medlineplus/pulmonaryembolism.html

Pulmonary embolism. Mayo Clinic Staff. September 26, 2009. https://www.mayoclinic.com/health/pulmonary-embolism/DS00429

Pulmonary Embolism. Sara F. Sutherland, MD, MBA, FACEP. Updated May 8, 2009. WebMD. https://emedicine.medscape.com/article/759765-overview

D-dimer. American Association for Clinical Chemistry. Last Reviewed April 14, 2007. https://www.labtestsonline.org/understanding/analytes/d_dimer/test.html