Respiratory acidosis is that in which the blood pH is low due to increased retention of carbon dioxide caused by the lowering of the respiratory frequency or by pulmonary diseases that impair the gas exchange. So the cause of the respiratory acidosis is the pulmonary respiration. Metabolic acidosis is that in which the blood pH is low not due to the pulmonary retention of carbon dioxide but due to metabolic disturbances. Some metabolic disturbances result in liberation in the blood of nonvolatile acids that release hydrogen ions lowering the blood pH (e.g., diabetic ketoacidosis).
Respiratory alkalosis is that in which the pH is high due to increased expelling of carbon dioxide caused by elevated respiratory frequency. Metabolic alkalosis is the alkalosis caused by metabolic disturbances that increase the concentration of bases (alkalis) in the blood.
