What health risks are there for someone who drinks nothing but coffee?

The caffeine is going to have less and less of an effect on you. It can lead you to becoming dehydrated as your body uses water to remove the caffeine from your system. Coffee is acidic so it can give so it can give you heartburn and damage ulcers. Also one of the chemicals in coffee (doesn’t matter whether its decaf or not) cause the valve at the top of your stomach to relax, which can lead to acid reflux. I’m sure there are a few other things that it can damage in your digestion track. To much coffee can lead to iron deficiency anemia and interfere with your body absorbing iron supplements. And then it can stain your teeth also.

Thats all I can think of right now.

yes, you need drink lots of water or juice too. A friend of mine’s mother got put in the hospital she was so dehydrated from just drinking coffee. me personally i tend to drink one cup in the morning thats it, something isn’t right to me drinking it any other time lol

The mass amount of caffeine could be fatal.