癙

癙 names worry-linked illness or a draining sore. In the Shijing (Book of Songs, a classical Chinese poetry collection), commentators read 癙 in “癙憂以痒” as illness brought on by inward distress. The Shanhaijing (an early Chinese collection of myths and geography) and later medical dictionaries also give 癙 a sore or fistula sense: an abnormal channel that drains fluid.

癙 is formed by adding 疒, the illness component, to 鼠, making it a specialized illness word built from 鼠. 鼠瘻 and 瘻瘡 are related historical medical terms, not interchangeable definitions of 癙.

If someone sends 癙, what should you read?

It reads as deliberate classical or medical wording. Without a surrounding phrase, the character alone cannot tell you whether the sender means worry-linked illness or a draining sore; ask for the sentence around it.