What is the Creatine Kinase test?

The Creatine Kinase (CK) blood test measures the level of creatine kinase, an enzyme found mainly in skeletal muscle, heart muscle, and the brain. CK is released into the bloodstream when muscle cells are damaged or stressed.

Because CK rises in response to muscle injury, inflammation, or excessive strain, it is widely used to assess muscle health and integrity. Levels can increase after intense exercise, trauma, injections, or in certain medical conditions affecting muscle tissue.

The test is commonly requested in sports medicine, neurology, general medicine, and when investigating unexplained muscle symptoms.

Why do I need a Creatine Kinase test?

Creatine Kinase testing is useful when muscle damage or muscle stress is suspected, whether due to physical activity, injury, medication, or underlying disease.

It helps distinguish normal post-exercise muscle strain from clinically significant muscle injury.

You may need a Creatine Kinase test if you experience:

• Muscle pain or tenderness
• Muscle weakness
• Muscle stiffness or cramps
• Dark or cola-coloured urine
• Unexplained fatigue after exertion
• Muscle injury or trauma
• Suspected overtraining
• Use of medications affecting muscles (e.g. statins)

CK testing is also used to monitor recovery and assess the severity of muscle involvement.

Benefits of the Creatine Kinase test

• Detects muscle damage
  CK rises when muscle cells are injured.
• Assesses exercise-related strain
  Useful in athletes and active individuals.
• Supports investigation of muscle pain or weakness
  Helps clarify muscular causes.
• Monitors medication-related muscle effects
  Commonly used with statin therapy.
• Aids assessment after injury or trauma
  Reflects muscle tissue breakdown.
• Simple and widely used blood test
  Requires only a blood sample.
• Useful for monitoring recovery
  Tracks CK reduction as muscles heal.
• Supports clinical decision-making
  Helps guide further investigation or rest.

Step by step – how the test works

You can access Creatine Kinase testing UK-wide through two options:

1. Clinic appointment
   Choose your nearest UK clinic, where a healthcare professional will take your blood sample.
2. At-home or hotel visit (£60 extra)
   A qualified phlebotomist comes to your home or hotel, so you don’t need to travel.

Your sample is analysed in an accredited UK laboratory, and results are delivered securely.

Your results explained

Low CK levels

Usually considered normal and indicate no significant muscle damage.

Typical UK reference range:

• Within laboratory reference interval

Normal CK levels

Suggest healthy muscle tissue with no active muscle breakdown.

Typical UK reference range:

• Men: ~ 40–320 U/L
• Women: ~ 25–200 U/L

High CK levels

Indicate muscle damage or stress. Levels may rise after intense exercise, injury, inflammation, or in certain muscle or neurological conditions.

Typical UK interpretation:

• Mild elevation: recent exercise or minor injury
• Marked elevation: significant muscle injury or disease

Reference ranges vary by laboratory, sex, and activity level.