Creatine kinase 252 U/L is in the elevated category. The normal range for creatine kinase is 18.0 to 198.0 U/L. Creatine kinase, also known as creatine phosphotransferase, is a kinase that catalyzes the phosphorylation of creatine by ATP and its inverse reaction, and plays an important role in biological functions such as ATP regeneration, muscle contraction, and cellular energy transport. Elevated creatine kinase first needs to urgently rule out the presence of myocardial infarction, myocarditis and other cardiac diseases, which are usually accompanied by chest pain and electrocardiogram (ECG) changes; followed by a history of prolonged and heavy exercise, taking statin lipid-modulating drugs; and then myotonic dystrophy, polymyositis and so on. If you have elevated creatine kinase, you need to go to the hospital and have your doctor evaluate the cause and develop a treatment plan.