Thrombosis is a serious medical problem: a clot — a small lump of thickened blood — forms inside a blood vessel and blocks the blood from flowing normally.

Thrombosis is a serious medical problemThrombosis(血栓症)是一種嚴重的醫療問題： a clot — a small lump of thickened blood —一個血栓——一小塊變厚凝結的血—— forms inside a blood vessel在血管裡形成 and blocks the blood from flowing normally擋住血液，讓它沒辦法正常流動。

Your blood is supposed to clot when you cut yourself, to stop the bleeding. Thrombosis is that same useful process happening in the wrong place, inside a vessel where nothing should be blocking the way. It is dangerous because the part of the body past the block stops getting blood, and because the clot can break loose and travel to the lungs or the brain.

Your blood is supposed to clot when you cut yourself你受傷流血的時候，血本來就應該凝結， to stop the bleeding才能止血。 Thrombosis is that same useful process happening in the wrong placeThrombosis就是同一個有用的過程發生在錯的地方 inside a vessel where nothing should be blocking the way在一條原本不該有東西擋路的血管裡。 It is dangerous because the part of the body past the block stops getting blood這很危險，因為血管阻塞點之後的身體部位會得不到血液， and because the clot can break loose and travel to the lungs or the brain而且血栓也可能鬆脫、跑到肺部或腦部。

You will hear it most often in two phrases: 'deep vein thrombosis' (often shortened to DVT), a clot in a deep vein of the leg, which is the one people worry about on long flights; and 'coronary thrombosis', a clot in the vessels of the heart. It is a doctor's word, not an everyday one — in normal conversation people say 'a blood clot'. The plural is thromboses.

You will hear it most often in two phrases你最常會在兩個詞裡聽到它： 'deep vein thrombosis' (often shortened to DVT)'deep vein thrombosis'（深部靜脈血栓，常縮寫成DVT）， a clot in a deep vein of the leg指的是腿部深層靜脈裡的血栓， which is the one people worry about on long flights也就是搭長途飛機大家會擔心的那種； and 'coronary thrombosis', a clot in the vessels of the heart還有'coronary thrombosis'（冠狀動脈血栓），指的是心臟血管裡的血栓。 It is a doctor's word, not an everyday one這是醫生用的字，不是日常用語 — in normal conversation people say 'a blood clot'——平常聊天大家會說'a blood clot'（血塊）。 The plural is thromboses複數形是thromboses。