Low blood carbon dioxide is hypocarbia, which can be seen in metabolic acidosis or respiratory alkalosis, and the treatment is mainly symptomatic. 1. Compensatory metabolic acidosis can cause low blood carbon dioxide, which can be seen in renal failure, diabetic ketoacidosis and other diseases, the treatment is mainly symptomatic. Hypocapnia caused by renal failure can be sodium bicarbonate intravenous drip. Low carbon dioxide caused by diabetic ketoacidosis, should actively control blood glucose, such as pumping insulin, a large number of rehydration, correct electrolyte disorders. 2. Low carbon dioxide can also be seen in respiratory alkalosis, mainly due to hyperventilation, can be seen in emotional excitement, high fever, etc.. The main treatment is to keep calm and avoid emotional excitement. Those with high fever should be actively cooled down, such as the use of ibuprofen. Low blood carbon dioxide is a kind of pathological change, and should seek medical treatment in time and standardize the treatment under the guidance of doctors.