It is my opinion that with magic, as with anything else, there is an equal and opposite reaction. It is basic physics. Before doing anything, you must understand all of the possible repercussions, and consider the entire situation logically. If you throw a punch, you start a fight. You push something, it moves, falls over, or pushes back. Etc.
Using energy has its own consequences. It can leave you light headed, dizzy, nauseous, etc. It all depends on you, what energies you use, how balanced you are, if you are grounded, etc.
There are numerous factors to consider.