What Causes Intermittent Loss Of Consciousness And Memory Loss?

hi doctor, I m very concerned about my fathers health. He has been smoking and drinking for several years now and I don t know if he try s to stop or not but every once in a while he will fall and won t respond. His acts like he is having some type of attack in his system. My and my brother then have you scream at him and hit him until he comes back. He isn t aware of what happened and acts like everything is okay. My and my brother try to talk with him but he is a stubborn guy. He is only 50 and I really don t want to lose him to something he can stop. What should I do