[3] Clinically, creatine kinase is assayed in blood tests as a marker of damage of CK-rich tissue such as in myocardial infarction (heart attack), rhabdomyolysis (severe muscle breakdown), muscular dystrophy, autoimmune myositides, and acute kidney injury.

CK-BB is predominantly expressed in brain and smooth muscle, including vascular and uterine tissue.

[7][8] The atomic structure of the banana-shaped, dimeric cytosolic brain-type BB-CK was solved in 1999 at a resolution of 1,4 Å.

[9] Cytosolic BB-CK, as well as muscle-type MM-CK both form banana-shaped symmetric dimers, with one catalytic active site in each subunit.

[2] Thus, CK enhances skeletal, cardiac, and smooth muscle contractility, and is involved in the generation of blood pressure.

It used to be determined specifically in patients with chest pain to recognize acute myocardial infarction, but this test has been largely replaced by troponin.

[17] Finally, high CK in the blood may be an indication of damage to CK-rich tissue, such as in rhabdomyolysis, myocardial infarction, myositis and myocarditis.

This means creatine kinase in blood may be elevated in a wide range of clinical conditions including the use of medication such as statins; endocrine disorders such as hypothyroidism;[18] and skeletal muscle diseases and disorders including malignant hyperthermia,[19] and neuroleptic malignant syndrome.