economy-class syndrome
noun [ U ] informal uk/ɪˈkɒn.ə.mi.klɑːs ˌsɪn.drəʊm/ us/ɪˈkɑː.nə.mi.klæs ˌsɪn.droʊm/
经济舱综合症（指因乘坐飞机导致静脉或肺部血管血液粘稠）
deep vein thrombosis (= a sticky mass of blood in the lungs or in the tubes that carry blood to the heart) that someone develops after travelling on a plane