When Can A Person Be Described As Mad?

In a literal sense the word 'mad' describes a scientific phenomenon in which a person starts behaving in such a way that cannot be considered normal and the behaviour may also harm the people who are living close to him.
      
But when you can also described a person as mad when he acts like he is absolutely without sense and in his foolishness he created hell out of his life. You might have come across this kind of person in several situations where he takes some wrong decision when it is obvious that if that decision is implemented, it will bring havoc to the people involved in it, but still the mad person performs the act. Certainly such an act is madness and the person can be described with the title of mad. So if you find some one who is behaving like a mad person you are advised to keep your distance from him as it may harm you also.