Mental health affects physical health because If you are not mentally stable and able to take on life with the fullest of awareness that will take a toll on your brain and that could lead to you lashing out on yourself physically. If you feel that you are not enough that is a state of the mind. A state of the mind that may make you physically lash out on yourself by cutting yourself, physically punishing yourself or continually telling yourself your not good enough which is a form of self mental abuse it makesyou think the world would be better off without you and make you do something you might regret.