High lactate dehydrogenase is not harmful in itself, but is mainly caused by the disease that causes high lactate dehydrogenase. Lactate dehydrogenase is widely found in the heart, liver, kidneys, skeletal muscles, etc. If abnormalities in these organs occur, lactate dehydrogenase may be elevated. If abnormal diseases of these organs occur, it will lead to an increase in lactate dehydrogenase, such as myocardial infarction, acute and chronic hepatitis, liver cancer, blood diseases, pulmonary infarction, etc. Therefore, if high lactate dehydrogenase is found, it is necessary to combine the relevant symptoms to determine what is the real disease causing high lactate dehydrogenase, so that the diagnosis can be further confirmed and the disease can be treated to reduce the harm caused by the disease.