In the play, Mozart died of a sicknes. What did Mozart die of real life?
Toward the end of his life, Mozart suffered from pain, swelling, fevers, and vomiting. All of these were symptoms of rheumatic fever. This disease is often brought on after a severe bacterial infection like strep throat or scarlet fever. Given the extreme stress Mozart lived under in his adult life, it is no surprise his immune system was weak and susceptible. A person can suffer with the disease for several years, during which time it will affect the heart. The weakening of the heart for a prolonged period of time eventually leads to a heart attack
Today, rheumatic fever is not an automatic death ticket as it can be easily treated with antibiotics. Medicine was not advanced enough in Mozart's day to know this, in fact, many originally thought he had been poisoned to death.
I have just asked my History teacher, who studied famous composers a few yeas ago. He believe that Mozart died of a terrible fever which he caught when he visited Prague in 1791. It was written that his body contained terrible symptoms, meaning the the fever must have been deadly.