D-DIMER, QUANTITATIVE

What this test checks

Measures D-dimer, a clot-breakdown product. High levels suggest active clotting; very low levels essentially rule out a major clot.

Why do people get this test?

Used when blood clots in the lungs (pulmonary embolism) or legs (DVT) are suspected.

When you should consider this test

• Sudden shortness of breath
• Swollen, painful leg
• Suspected blood clot

How to prepare

No fasting needed.