pH is a measure of hydrogen ion (H+) concentration. A measure of the concentration of hydrogen ions (H+) in a solution is called the pH of the solution. The neutral pH value of the body is 7.0. Body fluids are acidic if the pH value is less than 7.0 and alkaline if it is higher. The ideal blood pH value is 7.4. A pH value below or above 7.4 can cause death in humans.
Buffer solutions can resist pH value changes.