The word mad is the term that in our language we use to refer to that person whose mental faculties are unbalanced, that is, put in simpler words, crazy is he who has lost his mind.
The madman suffers from the disease of the craziness, which implies a mental imbalance and that causes the individual who suffers from it to present various characteristic symptoms such as: distorted perception of the reality that surrounds him, loss of control with which they will send uninhibited actions and expressions, appearance of hallucinations, display of compulsive and meaningless behaviors , among the most recurrent.
Then, the symptoms can be very varied and some appear more clearly more than others, depending on the case, although the departure from reality is the one that best marks the situation.
On the other hand, the word crazy also presents a frequent use at the behest of colloquial language to refer to various issues.
When someone displays some action, behavior, that stands out for its recklessness It is common for us to speak in terms of madness and madness to refer to the fact. In other words, in this case there is no pathology present but it is simply an inconsiderate and foolish action or behavior. You're crazy you can't get through two red lights.
But there are more uses of the term in common language such as: to express what goes beyond the limits of the common, the usual (inflation in the country is crazy); when you want express a huge desire or enthusiasm for something (people were crazy to take out the Chayanne tickets); and to that system not working satisfactorily (my computer went crazy, it won't turn off).
There is also a significant number of popular expressions that contain the word crazy, such as: no way (It is the same to say in no way); To each his own theme (when a person insists too much on a question); crazy about this or that (to express that someone is in love); play dumb (to appear to be unaware of something); and wildly (when something is not reflected).
