All tests › Pancreas and muscle enzymes

Creatine kinase

Pancreas and muscle enzymes · CK · also printed as CK, Creatine kinase, Total CK, Creatinine kinase, CPK

Typical UK adult rangebelow 308 U/L

Women: below 200 U/L · Men: below 308 U/L

Upper limits printed in the UK are commonly 200 U/L for women and 308 U/L for men, and higher in people of Black African ancestry.

What this test measures

Creatine kinase, CK, is an enzyme found mostly in skeletal muscle and the heart. It leaks into the blood when muscle is damaged or has worked very hard.

Why doctors request it

Doctors request it for muscle pain or weakness, before and during statin treatment, and after very heavy exercise or falls.

What commonly pushes it up

Heavy exercise in the previous few days
A fall, injury, injection or surgery
Statins and some other medicines as a class
Muscle inflammation or muscle disease
An under-active thyroid
Being of Black African or Caribbean ancestry, where typical values run higher
Seizures

What commonly pushes it down

Low muscle mass
Long periods of inactivity

Everyday reasons for a value outside the range

A gym session or long run two or three days earlier is the commonest reason for a raised value
Typical ranges differ by sex, muscle mass and ancestry
Values several times the upper limit occur after intense exercise without any illness

About the sample

Avoid strenuous exercise for three days before the test where possible.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.

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This is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.