There are some hangups that can kill you if you’re not careful. A man from Chongqing, China, developed a fungal lung infection after regularly smelling his own dirty socks when he came home from work every day. He was hospitalized with a persistent cough and bloodshot eyes, and doctors diagnosed him with an Aspergillus infection in his lungs.
Doctors got a pair of his dirty socks and tested them, which showed that his socks contained the fungus, likely due to the warm, moist environment inside shoes that promotes fungal growth. Doctors advise to not get in the habit of smelling dirty socks for fun, which is advice they probably never thought they’d have to give.
Source: Oddity Central