To stay healthy, your body needs to keep the pH level of your blood within a pretty narrow range: between 7.35 and 7.45. To maintain this level, your blood creates its own buffer system consisting of molecules that absorb excess hydrogen ions if things get too acidic, or release them if the blood is too basic.

Without this system, your blood would become either too basic or too acidic for your body's enzymes to go about their business, toxins would accumulate at warp speed, and after a short time, you'd die.