Low creatine kinase may be associated with physiologic causes, drug effects, muscle injury, and hyperthyroidism. After active treatment, it can usually be improved. 1. Physiological reasons: usually if overwork or mental stress, sleep quality decline and so on may trigger creatine kinase lowering. 2. Drugs: If you take steroids or other drugs to treat your disease, it may trigger a decrease in creatine kinase. 3. Muscle injury: if the skeletal muscle or heart muscle is injured, it is easy to trigger the decrease of creatine kinase in the body. 4. Hyperthyroidism: For patients with hyperthyroidism, an increase in thyroid function will affect the level of hormones in the body, thus triggering a decrease in creatine kinase. In clinical medicine, low creatine kinase test results are not of great clinical significance. With appropriate activities, enhanced nutrition and active treatment, the abnormal creatine kinase can usually be improved.