pH

pH, measure of hydrogen gas in a solution. apH of 7, which is neutral (neither acid nor alkaline), means there are 100 nanoequivalents of hydrogen ions per liter of blood. The human body functions best when the blood pH is 7.40, that is, when it contains about 40 nanoequivalents of hydrogen ions per liter. Therefore, the blood is normally very slightly alkaline. When the pH goes below 7.38, normal body functions are disrupted and the pathological, possibly fatal conditions of acidemia (acidosis) exists. Should hydrogen ions be lost from the body (or neutralized) and the blood pH rise above 7.44, alkalemia (alkalosis) occurs. Either condition reflects an acid-base balance disturbance. Breathing out carbon dioxide (which is acid) helps keep the pH properly balanced. The pH is measured in blood, urine, spinal fluid, lung fluid, semen, and many other body secretions.