The creatine phosphokinase test ;measures the amount of creatine phosphokinase (CPK) present in the blood. The test is also known as a creatine kinase test, CPK test, or CK test.
Creatine phosphokinase is a specific enzyme found primarily in the heart, skeletal muscle, and brain tissues.
The creatine phosphokinase test is performed to assess damage to tissue in the brain, muscle tissue, or heart. When tissue is damaged, creatine phosphokinase leaks from tissue into the blood.
The test is used to diagnose and evaluate the following conditions:
- a heart attack
- chest pain
- muscle damage
- early dermatomyositis, which is a muscle and connective tissue disease
- polymyositis, which causes inflammation of the muscles
- muscular dystrophy
It’s also used to differentiate between postoperative infection and malignant hyperthermia, which is a fast rise in body temperature.
The creatine phosphokinase level is usually measured in a blood sample taken by a healthcare professional. The blood test usually involves these steps:
- They’ll wrap an elastic band around your upper arm to stop the flow of blood. This also causes the veins in your arm to become more visible, so the needle can be more easily inserted.
- Alcohol is used to clean the site on your skin where the needle will be inserted.
- The needle is inserted into your vein. This may cause a brief pinching or stinging sensation, or you may not feel anything at all.
- They’ll attach a tube to the needle to collect blood. Sometimes, more than one tube is needed.
- The elastic band is removed after enough blood has been collected.
- As the needle is removed from your skin, cotton or gauze is placed on the site of the injection.
- Pressure is applied to the area, and a bandage is used to secure the cotton or gauze.
As the needle is inserted into the vein, you may feel a stinging or pinching sensation, mild discomfort, or you may feel nothing at all.
After the blood has been collected, the sample is sent to a lab so the level of creatine phosphokinase in the blood can be measured. If you’re an inpatient in the hospital, the test may be repeated over a few days.
When high levels of creatine phosphokinase are detected in the blood, it’s considered to be an abnormal result. High levels of the enzyme may occur due to the following conditions:
- a heart attack
- pericarditis after a heart attack
- polymyositis or dermatomyositis
- heart muscle inflammation
- myopathy, which is a disease of the muscles
- rhabdomyolysis, which is a breakdown of muscle tissues
- a muscular dystrophy
- an electric shock
- a stroke
- a brain injury
- delirium tremens, which is caused by alcohol withdrawal
- hypothyroidism, which is characterized by an underactive thyroid gland
- hyperthyroidism, which is characterized by an overactive thyroid gland
- the death of lung tissue
The creatine phosphokinase test has few, if any, risks. It’s an important test for a number of conditions. Talk to your doctor if you’re going to have this test and you’re concerned about the process or potential outcomes.