(Note that this just a joke and is not real so please don't take it seriously)
Joaquin Phoenix Joke Disease is a hugely rare disease that makes a person laugh uncontrollably until they physically cannot breath. This usually accures when something funny is said to the person or if the person thinks of something they think is funny. The meaning behind the disease's name is from Joaquin Phoenix, who is famous for playing Joker in the DC film of the same name. In the film, he suffers from a illness very similar to this where he will laugh miniacly without his free will. Side effects of Joaquin Phoenix Joke Disease include, laughing uncontrollably, sore throat and lungs, unable to control breathing processes and even death.
Person 1: *says something funny*
Person 2: *starts laughing uncontrollably for several minutes*
Person 1: wow dude are you okay??
Person 2: yeah I'm fine I just have Joaquin Phoenix Joke Disease, it happens all the time.
Person 1: Oh okay see you later bro.
Person 2: *continues to laugh and choke cutely in Japanese*