How can superficial vein thrombosis (SVT) be differentiated from deep vein thrombosis (DVT)?

Differentiating superficial vein thrombosis (SVT) from deep vein thrombosis (DVT) relies significantly on physical examination findings, and the presence of a palpable "cord" is a key characteristic of SVT. When palpating the affected vein in cases of SVT, you may feel a hardened, cord-like structure along the vein, which indicates inflammation and thrombosis in the superficial venous system. This finding is specific to SVT and not typically present in DVT.

In contrast, DVT usually involves deeper veins that are not accessible for direct palpation, making it harder to assess through physical examination alone. Therefore, while imaging techniques like Doppler ultrasound can be utilized for confirmation, the simple physical sign of a superficial "cord" gives a clear indication of SVT.

Blood flow evaluation methods such as CT scans and D-dimer level checks may assist in diagnosing DVT or ruling out thrombosis, but they do not provide the direct and specific clinical evidence for distinguishing SVT from DVT that the palpable cord does. Thus, the ability to palpate a "cord" is an essential clinical indicator for diagnosing SVT.