When blood becomes more acidic than normal, the condition is called acidosis. Clinically, acidosis refers to a process that pushes the body’s acid–base balance toward excess acidity, usually reflected by a blood pH below the normal arterial range of 7.35 to 7.45.
There are two major forms. Respiratory acidosis develops when the body cannot remove enough carbon dioxide through the lungs, allowing acid-producing carbonic acid chemistry to shift blood pH downward. Metabolic acidosis occurs when acids accumulate, bicarbonate is lost, or the kidneys cannot remove acid effectively. Diabetic ketoacidosis and lactic acidosis are important examples.
Acidosis is often confused with acidemia. Acidosis describes the underlying process, while acidemia describes the measured state of low blood pH; several disorders can occur together and partially offset one another. The opposite disturbance is alkalosis, in which body fluids become too alkaline. The lungs and kidneys work together to keep blood pH within its narrow safe range.