Measurement of D-Dimer Levels in Patients With Confirmed Deep Vein Thrombosis

Inclusion Criteria: * The study population tested will be recruited from ambulatory outpatients (presenting at the emergency unit or outpatient clinic) suspected of having DVT. * Patient is \< 80 years old. * Patient presenting at least one of these symptoms indicative of proximal DVT: leg pain, tenderness (discomfort through palpation), leg swelling and /or edema, * Patient has confirmed proximal DVT by imaging * Low or moderate Wells score * Patient provides written informed consent to participate in the sample collection Exclusion Criteria: * Patient presenting with a condition that may be associated with increased D-dimer levels, even in the absence of VTE, such as: 1. Fibrinolytic therapy within the previous seven (7) days, 2. Bone fracture or surgery (with general anesthesia longer than thirty (30) minutes) within the previous one (1) month, 3. Deep hematoma diagnosed by imaging techniques within the previous one (1) month, 4. Disseminated malignancies and active cancer (active cancer defined as: cancer for which therapeutic or palliative treatment is either ongoing at the time of enrolment or has stopped less than six (6) months before enrolment), 5. Sepsis, severe infections, pneumonia within the previous 1 month, 6. Known liver cirrhosis, 7. Pregnancy or post-partum within the previous 1 month, 8. Atherosclerotic vascular disease thrombosis within the previous 1month (e.g. myocardial infarction, stroke, coronary syndrome, peripheral artery disease stage III or IV), 9. Sickle cell disease, * Patients presenting with a suspect thrombotic event related to catheter implantation * Ongoing therapeutic anticoagulants (curative and preventive treatment) starting twenty four (24) hours or more before the blood drawing for D-dimer testing