Stuffy Nose
Blocked Nose
noun
詰まる is "to be stuffed." So, if your nose is stuffed, then you have a stuffy nose.
The reading is 鼻 and 詰まる put together. the 詰まり is rendaku'd, probably because you're trying to say this word with a stuffy nose.
私は高熱と鼻詰まりに苦しんでいます。
I’m suffering from a terrible fever and stuffy nose.