Phosphocreatine kinase, found mainly in skeletal muscle, heart muscle and brain tissue, is an enzyme involved in energy metabolism in the body. It can be used to diagnose diseases such as myocardial infarction, viral myocarditis, and cerebrovascular accidents. 1. Myocardial infarction: In myocardial infarction patients, phosphocreatine kinase increases within 2-4 hours after the onset of myocardial infarction, which precedes the appearance of glutamic acid-oxaloacetic acid aminotransferase and lactic acid dehydrogenase, so it is important for the early diagnosis of myocardial infarction. 2. Viral myocarditis: In patients with viral myocarditis, phosphocreatine kinase is also elevated. 3. Cerebrovascular: ischemic cerebrovascular, hemorrhagic cerebrovascular, intracranial cerebrovascular malformation, aneurysm, and atherosclerosis can lead to elevated phosphocreatine kinase. Symptoms such as dizziness, nausea and vomiting may occur before the onset of the disease. When phosphocreatine kinase is elevated, it is recommended to go to the hospital for further examination and diagnosis.