11Flesh-Eating Diseases: These types of diseases are exactly like they sound: absolutely terrible. They navigate to the deepest layers of the skin and begin to kill tissue from the inside out. This leads to the rotting and decay of the infected areas. Typically, we see discolored, blistered skin with fluids leaking out of it. The only way to get rid of these diseases is through surgery, and about 73% of people who get them will die if left untreated.