idiom · The disease has reached the vitals; medically incurable or at a terminal stage.

他直到病入膏肓才去医院，结果已经无力回天。

idiom · A situation, state of affairs, or habit that is so far gone it is beyond remedy.

这家公司的腐败问题已经到了病入膏肓的地步，很难彻底整顿。