Lactate dehydrogenase 407 U/L does not indicate severity. Lactate dehydrogenase is an enzyme present in the cells of the body, and the normal value of the test is usually not more than 245 U/L, but the elevation does not necessarily mean that there is an organic lesion of the organs. This enzyme is often used in the clinical examination for the examination of heart diseases, but this index is not specific, and other diseases may also cause the elevation of lactate dehydrogenase, such as liver or kidney diseases. Coronary arteriosclerotic heart disease, acute infarction, myocarditis, and other heart diseases are the main causes of elevated lactate dehydrogenase. In liver diseases, the main causes of lactate dehydrogenase elevation are chronic alcoholic liver injury, chronic hepatitis, and cirrhosis. Lactate dehydrogenase is also elevated in kidney diseases such as renal failure and glomerular disease. Other diseases such as malignant tumors and muscle injuries can also cause elevated lactate dehydrogenase. Lactate dehydrogenase abnormality alone cannot directly determine what kind of organ is abnormal, nor can it indicate that it is serious, it is only one of the auxiliary tests, but also according to the patient’s specific symptoms, as well as the results of laboratory and imaging tests to make a comprehensive judgment.