» For acidosis referring to acidity of the urine, see renal tubular acidosis. Acidosis is an increased acidity (for example an increased hydrogen ion concentration). If not further qualified, it refers to acidity of the blood plasma. Acidosis is said to occur when arterial pH falls below 7.35, while its counterpart (alkalosis) occurs at a pH over 7.45. Arterial blood gas analysis and other tests are required to separate the main causes. The term acidemia describes the state of low blood pH, wh… (More on Acidosis)