zhè zhǒng / jí bìng / zǎo qī / zhèng zhuàng / bù míng xiǎn / yì jīng / fā xiàn / wǎng wǎng / yǐ shì / zhòng zhèng

这种疾病早期症状不明显，一经发现往往已是重症。

This disease has no obvious symptoms in its early stage, and once it is discovered, it is often already severe.