Does my dad have alzheimers or demensia?

Anonymous
My dad is 64 and he is starting to do things that make no sense. He acts like he is absoluetly stupid. Today he yelled at me becasue he didn't know what the +1 was in front of his number... he didn't know that was a dialing code! Then he has a hard time comprehending or understanding people. He gets mad easily, he forgets things that he should never forget. (Like things that he does as an everyday routine) his judgment is starting to change drastically. He is obsessed with cleaning and organizing. I had to explain what OCD was but somehow he has never heard of that being on this earth for over 40 years.. he doesn't know things that an average person or adult should. Whats going on with him? This started about a few months ago.
Does my dad have alzheimers or demensia?
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