Creatine kinase (CK)

Pick Ordered or Not ordered to see the note.

Indicated when

• —Muscle pain, weakness, or dark urine suggestive of myopathy or rhabdomyolysis, including new muscle symptoms in a patient taking a statin, where CK is the standard test used to screen for a muscle problem before it progresses
• —As part of the baseline rule-out panel for widespread pain meeting the clinical pattern for fibromyalgia, alongside CBC, ESR/CRP and TSH, where the Canadian fibromyalgia guideline specifically includes creatine kinase in this panel and limits further testing to what the clinical evaluation suggests [1]

Not indicated when

• —Included in a routine wellness or hormone panel with no muscle symptoms, weakness, statin use, or fibromyalgia rule-out indication present

Why not

Outside these situations, CK is hard to interpret without a reason for testing: levels commonly rise for a few days after vigorous exercise, a fall or other muscle trauma, or an intramuscular injection, and these everyday causes of a mildly elevated result are not distinguished from early myopathy without a specific clinical context.

Better first step

Ask about statin use, recent vigorous exercise, trauma, or injections before ordering, and order CK when there is a specific reason, such as muscle symptoms, suspected myopathy, or as part of the fibromyalgia baseline panel, rather than as routine screening [1].

Typical ND rationale

An ND may include CK in a muscle or general wellness panel for a patient with fatigue, muscle aches, or on a statin, reasoning that it is an inexpensive way to catch a developing muscle problem, including a statin-related one, before it becomes more serious.

Ontario coverage & CONO orderability

OHIP status

insured

Creatine phosphokinase is listed by name (L066) in the 2026 Schedule of Benefits for Laboratory Services, insured when a physician who has clinically assessed the patient orders it. The same test ordered by an ND is patient-paid regardless (Reg. 552 s.22).

CONO orderable

Yes — CONO list #49

CONO list item 49, blood: 'Creatine Phosphokinase.'

Linked conditions

• "Should I be tested?" for fibromyalgia ↗

Counselling script

“If you're having muscle pain or weakness, especially on a statin, or we're working through a fibromyalgia assessment, checking creatine kinase makes sense, so I'll order it today. Without one of those reasons, I won't add it to routine bloodwork, since a high result after exercise or a minor injury usually just leads to more testing rather than finding a real problem. If new muscle symptoms come up later, including on a statin, let's check it then.”

Revisit if

• —New muscle pain, weakness, or dark urine
• —New muscle symptoms after starting or increasing the dose of a statin
• —Widespread pain being worked up for fibromyalgia

References

1. [1]Canadian Pain Society / Canadian Rheumatology Association (Fitzcharles MA et al.) (2012). 2012 Canadian Guidelines for the diagnosis and management of fibromyalgia syndrome: executive summary. linkolder guidelineRecommendation 4: FM diagnosed as a clinical construct, with testing limited to CBC, ESR, CRP, creatine kinase and TSH; any additional testing should depend on the clinical evaluation (level 5, grade D)
2. [2]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026) - L066 Creatine phosphokinase. linkCreatine phosphokinase (L066) is listed by name in the 2026 OHIP Schedule of Benefits for Laboratory Services
3. [3]Government of Ontario (e-Laws) (2026). Health Insurance Act, R.R.O. 1990, Reg. 552: General, s. 22 (insured laboratory services). linkA lab test is insured only when ordered by a physician, midwife, or NP who has clinically assessed the patient
4. [4]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkTests ordered by anyone other than an authorized provider, including NDs, are not insured services