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thrombus; blood clot
右足に血栓ができた。
A blood clot formed in my right leg.
医師は血栓を防ぐ薬を処方した。
The doctor prescribed medication to prevent blood clots.
肺にできた血栓が原因で呼吸が苦しくなった。
Difficulty breathing was caused by a blood clot that formed in the lung.