Is D-dimer Slightly Elevated in Most People?
No, D-dimer is not slightly elevated in most people in the general population—a normal D-dimer level is typically less than 0.5 μg/mL (500 ng/mL), and elevations above this threshold indicate active coagulation and fibrinolysis, which is not a normal physiological state. 1
Understanding Normal D-dimer Levels
- The standard cutoff for normal D-dimer is <0.5 μg/mL (500 ng/mL), and values above this are considered elevated and pathological, not a common finding in healthy individuals 1, 2
- D-dimer testing has a 99% negative predictive value when below the cutoff, meaning a normal result effectively excludes acute thrombotic disease in appropriate clinical contexts 2
- The test is designed to be highly sensitive but non-specific, meaning it catches nearly all cases of thrombosis when elevated, but elevations can occur in many other conditions 3
When D-dimer IS Commonly Elevated (Not "Normal")
While D-dimer is not elevated in most healthy people, it is frequently elevated in specific clinical populations, which is important to distinguish:
- Advanced age: Specificity decreases to as low as 10% in patients over 80 years old, which is why age-adjusted cutoffs (age × 10 ng/mL for patients >50 years) are recommended 3, 1
- Pregnancy: Levels progressively increase during pregnancy, with third-trimester values up to 1.3-2.0 μg/mL potentially being normal 1
- Hospitalized patients: D-dimer is more frequently elevated compared to outpatients 3
- Cancer patients: Elevated levels are common even without venous thromboembolism 3, 4
- Inflammatory conditions and infections: Including sepsis and severe inflammatory disease 3, 1
- Recent surgery or trauma: Post-operative and post-traumatic states 1
Clinical Significance of Elevated D-dimer
D-dimer elevations are pathological markers, not benign findings:
- Extremely elevated D-dimer (>5000 μg/L or >10× normal) is associated with serious illness in 89% of cases, predominantly venous thromboembolism (45%), sepsis (24%), and cancer (29%) 5
- Even moderately elevated D-dimer without VTE is associated with increased mortality and underlying malignancy 4
- D-dimer >0.5 μg/mL has 94-100% sensitivity for acute aortic dissection, making it an excellent rule-out test 1
Common Pitfall to Avoid
The critical error is assuming that because D-dimer can be elevated in many conditions, it is "commonly elevated" or "normal" in the general population—this is incorrect. The test's low specificity means that when it IS elevated, many non-thrombotic conditions can cause it, but the baseline state in healthy individuals is a normal D-dimer 3. The number needed to test to exclude one PE is only 3 in the general emergency department population, demonstrating that most people tested do NOT have elevated D-dimers 1.