The normal range is between 22-27 mmol/L in arterial blood, and a bicarbonate concentration in this range is considered normal. If it is not in this range, it can be used to detect the diagnosis of disorders of acid-base balance in the body, as well as a reference for specific typing. If the bicarbonate concentration is below the bottom limit, metabolic acidosis is considered, and above the high limit, metabolic alkalosis is considered. This is a preliminary diagnosis and must be combined with other blood gas analysis indicators, such as partial pressure of carbon dioxide, partial pressure of oxygen, as well as pH and residual alkali, to comprehensively evaluate the acid-base metabolism.