An elevation of the level of the enzyme creatine kinase (also known as creatine phosphokinase (CK; EC 2.7.3.2) in the blood. CK levels can be elevated in a number of clinical disorders such as myocardial infarction, rhabdomyolysis, and muscular dystrophy. The phenotype is Elevated circulating creatine kinase concentration (HP_0003236, a Human Phenotype Ontology entry). Also known as: Elevated blood creatine phosphokinase, Elevated circulating creatine phosphokinase, Elevated creatine kinase, Elevated serum CPK, Elevated serum creatine kinase, Elevated serum creatine phosphokinase, High serum creatine kinase, Increased CPK.