Psychology is a great example of a Pseudoscience. They mention Chemical inbalances but there has never been a test to prove that. Its just been indoctrinated into out society in advertisments and TV commercials that people accept it as fact. Everything a psychologist bases their diagnosis on is of a subjective nature. There is no objective test or blood test, no brain scan. Everything is subjective. They love to use the word "Soft Science"
Answer:
There are many different diseases, but i would say the flu.
Explanation:
I've gotten the flu before, and just in general sharing germs can get us sick.
Hepatitis A is the first one that come to mind.