Creatine kinase (CK) is an enzyme that is released into the bloodstream when there is muscle damage.
So serum creatine kinase is the blood test we order when we are concerned about the possibility of muscle damage
So when we see an elevated creatine kinase blood test, here’s a list of possible causes. (1)
1. Heart muscle injury: although CK is elevated in the heart muscle damage, the blood tests most often used for heart muscle damage are troponin T and troponin I
2. Trauma: bruising of muscles can lead to an elevated CK
3. Infections causing muscle disease or inflammation: viral, bacterial, mycobacterial, fungal, or parasitic
4. Endocrine diseases causing muscle damage: hyperthyroidism, hypothyroidism, Cushing’s disease, Addison’s disease, or acromegaly
5. Rheumatologic diseases or autoimmune diseases: vasculitis, thyroiditis, polymyalgia rheumatica, polymyositis for dermatomyositis
6. Drugs and toxins: colchicine, statins, zidovudine, and other drugs and toxins.
7. Metabolic causes of muscle damage: disorders of lipid metabolism, glycogen storage disease, and other metabolic disorders
8. Other causes: rhabdomyolysis, malignant hyperthermia, and seizures
(1) Critical Care Secrets, fifth edition, 2013. Parsons PE, Wiener – Kronish JP, pp 420 – 421.