Bicarbonate is the body’s alkaline ion, the level of bicarbonate concentration reflects the body’s acid-base state, and low bicarbonate means that the body is in an acidic state. In clinical practice, it is common in patients with metabolic acidosis and chronic renal insufficiency, as the body cannot excrete acidic substances such as uric acid out of the body in time. The patient is in a state of metabolic acidosis, and the concentration of bicarbonate in the body will be significantly lower. At the same time, low bicarbonate can be seen in patients with chronic and acute diarrhea, especially in patients with acute diarrhea, where there is a significant loss of intestinal fluid and a large amount of bicarbonate in the intestinal fluid, and after the loss of intestinal fluid, the bicarbonate concentration in the body will also be significantly reduced. For dehydration caused by acute diarrhea, in addition to supplementation of compound sodium chloride, sodium bicarbonate should be supplemented at the same time.