Troponin I is a protein found in heart muscle. It leaks into the blood when heart muscle is damaged.
- Normal range (adults)
- Below 0.04 ng/mL (below 40 ng/L)
- Sample
- Blood
- Fasting
- Not usually needed
- Also called
- Cardiac Troponin I, cTnI, TnI
Troponin I normal range
| Group | ng/mLConventional units: US, South Asia | ng/LSI units: UK, Europe, Australia, international |
|---|---|---|
| Adults | Below 0.04 | Below 40 |
Cut-offs depend on the exact assay. Always use the reference limit printed on your report.
Your report may use either unit system; labs in the Gulf often print both. Ranges also vary slightly between laboratories, so the range printed on your own report is the one to go by.
Why is the Troponin I test done?
It is the main blood test used in hospitals to diagnose a heart attack, usually measured more than once a few hours apart.
What does a high Troponin I level mean?
A raised troponin means heart muscle injury. A rising level with chest pain usually means a heart attack.
Common causes
- Heart attack
- Heart muscle inflammation (myocarditis)
- Heart failure
- Severe infection (sepsis)
- Pulmonary embolism
- Kidney failure (small chronic rise)
- Very strenuous endurance exercise
Diet and lifestyle tips
- This is a medical emergency result, not a diet issue. After recovery: heart-healthy eating with vegetables, whole grains, fish and olive oil
- Limit salt, fried food and processed meats
- Stop smoking
When should you see a doctor?
If you have chest pain, breathlessness or sweating, call emergency services immediately. Never wait for a troponin result at home.
Last updated
This page is for general education and is not a diagnosis. Normal ranges differ between laboratories, so always compare your result with the reference range printed on your own report, and discuss abnormal results with your doctor.