"The blood must maintain a pH between 7.3 and 7.45. (Guyton). If not, we die. With all the acid foods we keep eating, the body tries desperately to keep its pH within the range. The first things it tries are buffering with bicarbonates in the blood and lungs. (Guyton, p 392) Next, the body begins to sweep the extra acids into the tissues, especially muscles and joints. That's what lactic acid buildup comes from. If that's still not enough, as a final effort to keep from acidifying, the body will actually precipitate acids out of solution, in the form of solid crystals and salts. This is the exact mechanism of gallstones, kidneys stones, uric acid crystals, plaque, and cholesterol crystals. A built-in protection for self preservation. We think of these stones as major medical problems, but in reality it's just a sign that the body's systems are functioning as they should. Otherwise we'd be dead of acidosis."