The normal value of blood gas lactate is less than 1.6 mmol/L. In clinical practice, blood gas tests are of great clinical value in the assessment and evaluation of patients’ conditions. Especially in respiratory related diseases, patients with respiratory failure and disorders related to the internal environment, blood gas can show significant abnormalities, and the results of lactate and blood gas are important in determining the condition and adjusting the treatment plan for the corresponding clinical symptoms. If serum lactate values are significantly elevated in clinical practice, common problems include hypoxia and shock, both of which can result in elevated lactate values. In addition, elevated serum lactate values can also occur when patients are taking metformin, requiring discontinuation or change of medication if necessary.