metabolic acidosis, acidosis in which excess acid is added to the body fluids or bicarbonate is lost from them. Acidosis is indicated by a pH of blood below 7.4. In starvation and in uncontrolled diabetes mellitus, glucose is not present or is not available for oxidation for cellular nutrition. This glucose lack causes breakdown of fats for energy, resulting in acidic ketone bodies. The body uses plasma bicarbonate to neutralize these acids. Metabolic acidosis also occurs when oxidation takes place without adequate oxygen, as in heart failure or shock. Severe diarrhea, renal failure, ingestion of toxic substances (e.g., antifreeze or large doses of aspirin), and lactic acidosis also may result in metabolic acidosis. Hyperkalemia may accompany the condition. See also diabetic ketoacidosis.
