Creatine kinase levels usually reflect the condition of your skeletal muscles, heart, or brain. So, this test is recommended when you face any problems related to these organs. For example, if you show signs of a heart attack like chest pain, the doctor may suggest a CPK enzyme test along with others.

LDH is mainly used to check for tissue damage. Many types of acute (sudden) and chronic (long-lasting) conditions can damage tissues and cause high LDH levels. So LDH testing may be used in many different situations from bone and muscle injuries to monitoring treatment for cancer.

This test helps your healthcare provider figure out if you're having a heart attack. Measuring CK-MB used to be a common tool for diagnosing heart attacks, but healthcare providers use it less often today. Cardiac troponin is now the blood test of choice for finding a heart attack.