Normal values of creatine kinase are male: 38～174U/L, female: 26～140U/L (enzyme coupling method, 37℃); male: 15～163U/L, female: 3～135U/L (creatine colorimetric method). Values vary in different hospitals, organizations and test methods, and the above data are for reference only. Creatine kinase, also known as creatine phosphokinase, is mainly found in skeletal muscle, smooth muscle, heart muscle and brain, etc. It is an important kinase directly related to intracellular energy operation, muscle contraction and ATP regeneration. When damage occurs to the heart, brain, and skeletal muscle, such as myocardial infarction, viral myocarditis, dermatomyositis, myotonic dystrophy, cerebral infarction, and a variety of muscular disorders, intracellular creatine kinase can enter the blood vessels and increase the creatine kinase of the blood. Increases in creatine kinase are also seen in physiological conditions such as strenuous exercise or muscle strain. Decreases are most often seen in hyperthyroidism, which leads to increased metabolism and a decrease in creatine kinase in the blood. When there is a pathological increase or decrease in creatine kinase, you should go to the hospital in time to improve the examination and treatment under the guidance of the doctor.