D-dimer test - blood test, what a positive result means (2024)

FAQs

D-dimer test - blood test, what a positive result means? ›

A positive test means the D-dimer level in your body is higher than normal. It suggests you might have a blood clot or blood clotting problems. It's important to discuss blood test results with your doctor, who can explain what the results mean in your situation.

A normal D-dimer is considered less than 0.50. A positive D-dimer is 0.50 or greater. Since this is a screening test, a positive D-dimer is a positive screen.

High D-dimer levels are not always caused by clotting disorders. A few other possible reasons why you may have high D-dimer levels include pregnancy, heart disease, rheumatoid arthritis, and recent surgery. Being older or immobilized (unable to move) may also cause a high D-dimer level.

Modern D-dimer assays have reported sensitivities ranging from 95% to 96%, with specificities ranging from 45% to 61% and a negative predictive value (NPV) range from 97% to 99%. While highly sensitive, D-dimer assays are imperfect.

The negative predictive value of a baseline D-dimer level < 1.0 µg/ml was 90% for venous thromboembolism and 98% for pulmonary embolism (Fig. 1b). The positive predictive value for venous thromboembolism was 44% and 67% for D-dimer level ≥ 1.0 µg/ml and ≥ 3.0 µg/ml, respectively.

A positive test means the D-dimer level in your body is higher than normal. It suggests you might have a blood clot or blood clotting problems.

Statins which are traditionally used for high cholesterol have been proven to have anti-thrombotic properties and some of them like the lipophilic statins can lower D-dimer. These are sometimes prescribed for people with DVTs. You can read this ARTICLE which suggests 3 months use of statins can reduce D-dimer levels.

D-dimers are a marker for hypercoagulability and are linked with thrombotic events in patients with venous as well as arterial thrombosis.

Lipemia, a high triglyceride level, an elevated bilirubin level, an elevated serum rheumatoid factor level, or hemolysis may falsely increase the D-dimer level.

Mood was assessed with the Hamilton Rating Scales for Depression (Ham-D) and Anxiety (Ham-A). Mental stress elicited a hypercoagulable state as evidenced by increases in TAT and D-dimer, and by a decrease in t-PA.

What cancers cause positive D-dimer? ›

High D-dimer levels in malignancy are likely to reflect the biology of the underlying tumour, with higher levels observed in breast, prostate and bowel cancers.

However, according to the literature, D-dimer values greater than 500 ng/mL are considered positive.

Elevated levels of d-dimer are associated with inflammation and disease activity rather than risk of venous thromboembolism in patients with granulomatosis with polyangiitis in long term observation.

In summary, D-dimer test in combination with SGS pre-test could improve the accuracy of PE diagnosis. Patients with D-dimer levels over 1.96 mg/L (4 times of the normal level) have a significant risk for PE.

5 A second study concluded that infection, sepsis and cancer should be considered in patients with elevated D-dimer above the regular cut-off level of 500 µg/l. 9 In this study the prevalence of cancer and infection/sepsis was 6.3% and 35.9%.

A D-dimer level higher than 500 µg/L but below the age-adjusted cutoff ruled out the diagnosis of PE, with a 3-month risk of venous thromboembolism in line with that observed in patients with a D-dimer level lower than 500 µg/L or after a negative pulmonary angiography result, the gold-standard test for PE.