Creatine Phosphokinase Blood Test - Interpreting CPK Test Results

Enzymes are essential compound proteins that facilitate chemical changes in the body. The human system requires a mammoth variety of enzymes for its day to day functioning. One such enzyme is creatine phosphokinase (CPK) which is responsible for the working of the muscular system of the body. A CPK test is done to measure the level of this enzyme in the bloodstream.

Typically, CPK enzymes can be divided into three types – CPK 1 (found in the brain and lungs), CPK 2 (found in heart) and CPK 3 (found in skeletal muscle). When any of these parts suffer a damage, CPK enzymes are released in the blood. A CPK Test here checks for the presence and level of these enzymes and indicates the areas of injury.

Why is CPK Test Done?

A physician may recommend a CPK blood test in order to diagnose a heart attack, find the cause of chest pain or to evaluate the extent of damage caused to the heart muscles due to some internal or external factors. In addition to these, it may also be ordered to an individual to determine whether or not he/she is carrying the gene of muscular dystrophy, a type of disease known to cause weakness and muscle loss over time.

How is the test performed?

A CPK test is a simple blood test. A small amount of blood is drawn from one of the veins, usually from the arm which is carefully collected in a special blood sample tube. This sample is then sent to the laboratory for analysis and evaluation.

How to Analyse the Results?

The normal value of a CPK test is 10 to 120 micrograms per litre (mcg/L). Any deviation from this normal range is an indication of presence of some kind of problem in the body.

CPK 1 – This type of enzyme, as stated above is present in the brain and lungs. An elevated level of this enzyme means that there is either an injury in the brain due to a stroke or bleeding, a seizure, the presence of cancer in brain, or a pulmonary infarction (death of lung tissue).

CPK 2 – This enzyme type is found in the heart. An increased level of CPK 2 means there is an injury in the heart due to an accident, inflammation of heart muscle due to a virus or an electrical injury. An elevated level may also be due to an open heart surgery or heart defibrillation.

CPK 3 – Found in the skeletal muscles, the levels of CPK 3 may elevate due to a damage caused to the muscles of the body as a result of a crush injury; the muscles have been inactive for a prolonged period; damage inferred due to drug abuse or are inflamed.