Creatine kinase isoenzyme 40 requires active search for the cause and treatment of the original disease. If it is caused by cardiac diseases such as acute myocardial infarction, it needs drug treatment or even minimally invasive surgical treatment; if it is caused by skeletal muscle diseases such as progressive muscular dystrophy, it needs drug treatment. Creatine kinase isoenzyme mainly exists in cardiac muscle and skeletal muscle, the normal reference value <5%, if creatine kinase isoenzyme 40%, belongs to the high, commonly found in heart disease and some skeletal muscle disease. 1. Heart disease: the heart diseases that cause elevated creatine kinase isoenzyme include acute myocardial infarction, atrial fibrillation, etc. Coronary CT and electrocardiogram can be used to clarify the situation; stenting is feasible for acute myocardial infarction, and warfarin is given as a drug treatment for atrial fibrillation. 2. Skeletal muscle diseases: some skeletal muscle diseases such as progressive muscular dystrophy can also cause elevated creatine kinase isoenzyme, which can be clarified by electromyography and serologic examination, and medication such as glucocorticoid can be given, as well as rehabilitation or surgical treatment. If you find that creatine kinase isoenzyme is elevated, you need to find the cause in time and follow the doctor’s instructions to standardize the treatment, so as not to delay the condition.