Creatine Kinase (CK) Test
2,350 Kshs | Home Collection Available
Synonyms
None
Purpose
The Creatine Kinase (CK) Test measures the level of creatine kinase, an enzyme found predominantly in heart muscle, skeletal muscle, and the brain, in the bloodstream. When muscle tissue is damaged, whether from a heart attack, muscular injury, or neurological disorder, CK is released into the blood.
This test can help:
- Diagnose myocardial infarction (when used alongside troponin and CK‑MB isoenzyme measurements)
- Detect muscle diseases such as muscular dystrophy or polymyositis
- Assess the extent of muscle injury from trauma, strenuous exercise, or drug-induced damage (e.g., statin myopathy)
For a full diagnostic picture, the test can be performed alongside CK‑MB Isoenzyme, Troponin I or T, Lactate Dehydrogenase (LDH), Aldolase, and Myoglobin. Together, these tests give clinicians a clearer picture of where and how severe the muscle damage is, guiding diagnosis and treatment.
Patient Preparation
The patient should avoid exercise before venipuncture.
Samples
1ml with a minimum volume of 0.7ml of Serum or plasma collected in a Gel-barrier, red-top, or green-top tube (lithium heparin). Avoid using EDTA, oxalate, or citrate plasma. Serum or plasma should be separated from cells and should be avoided from prolonged contact with red cells. Store the sample at room temperature.
Reference Range
55-170u/l (units per litre)
Results Turnaround
Within 24 hours of sample receipt.
Diseases / Diagnostic indicators
The CK test helps identify and monitor muscle damage or disease by measuring enzyme levels released into the blood when muscle fibers break down. Some possible outcomes of the test include;
Elevated CK Levels
Indicate active muscle injury or disease. Common causes include:
- Rhabdomyolysis (rapid muscle breakdown)
- Muscular dystrophy and other myopathies
- Acute muscle trauma (e.g., crush injuries, intense exercise)
- Myocardial infarction (when CK‑MB isoenzyme is also elevated)
- Blood clots in muscle tissue
- Infections affecting muscle (e.g., viral myositis)
- Hormonal disorders such as hypothyroidism or hyperthyroidism
Normal CK Levels
- Suggest that there is no significant ongoing muscle damage.
Declining CK Levels after Elevation
- Indicate that the muscle injury is resolving and the body is clearing the enzyme from the bloodstream.
In clinical practice, elevated CK is interpreted alongside other markers, CK‑MB, troponin, myoglobin, and patient symptoms to pinpoint the source and severity of muscle or cardiac damage. For more on CK testing, read this study.