Troponin
Protein from heart muscle cells that enters the blood when the heart muscle is damaged
Also known as
Definition
Troponin is a protein found in the cells of the heart muscle. In the blood, it is normally so low that only very sensitive tests can detect it. When heart muscle is damaged, troponin leaks into the blood and the level rises. Either troponin T or troponin I is measured. The test is mainly used to confirm or rule out a heart attack and is usually done in the emergency department together with an ECG.
| Parameter | Value |
|---|---|
| Unit | ng/l (high-sensitivity tests) or ng/ml |
| Reference Range | No single range: in healthy people, troponin is very low. Cut-offs depend on the test (troponin T or I, high-sensitivity or not) and on the lab; the 99th percentile of the general population is often used as the threshold, sometimes separately by sex. The range on your own report is what counts; discuss your result with your doctor. |
Agree on your personal target range with your doctor.
1 ng/ml equals 1,000 ng/l. Results from different tests are not directly comparable.
↓ What a low value means
Low values are the norm. A normal first value does not yet rule out a heart attack, because troponin only rises a few hours after onset; that is why it is usually measured again. If the value is still normal twelve hours after symptoms began, a heart attack is unlikely. Persistent or new symptoms still need medical assessment, regardless of the value. Taking biotin can make troponin values appear falsely low.
↑ What a high value means
A raised value points to damage to the heart muscle; very high values are most often related to a heart attack. Raised values also occur with other causes, such as fast heart rhythm disorders, heart failure, heart valve disease, inflammation of the heart muscle, pulmonary embolism, sepsis, chronic kidney disease, chest injuries, after heart procedures or after long, intense exertion such as a marathon. After a heart attack, troponin can remain raised for one to two weeks. The result is always interpreted together with symptoms, ECG and other findings.
When to test
Troponin is mainly measured with chest pain or other signs of a heart attack, as well as with worsening angina and before and after surgery that may strain the heart. If you suspect a heart attack, call your local emergency number immediately. No special preparation is needed, but tell the care team if you take biotin.
Frequently asked questions
Is troponin part of a routine check-up? +
Primarily not. Troponin is mainly measured in emergency medicine when damage to the heart muscle is suspected. A single value can only be interpreted together with symptoms, medical history, ECG and other tests.
Why is troponin measured several times? +
After a heart attack begins, troponin only rises after a few hours and can keep increasing for around 24 hours. Several measurements over hours show whether and how much the value rises. This helps with the diagnosis and with estimating how much of the heart muscle is affected.
Can intense exercise raise troponin? +
Yes. Long, intense exertion such as a marathon or triathlon is listed as a possible cause of raised values. What a raised value means in your case is for your doctor to clarify.
How does biotin affect the test? +
Biotin (vitamin B7) and supplements containing biotin can make troponin values appear lower than they really are. So mention it before your blood draw. Do not stop any supplement on your own; discuss it with your doctor.
Troponin
Sources
- MedlinePlus, National Library of Medicine: Troponin Test
- MedlinePlus, National Library of Medicine: Troponin test (Medical Encyclopedia)
- NICE, National Institute for Health and Care Excellence: High-sensitivity troponin tests for the early rule out of NSTEMI (HTG552), Recommendations
- NICE, National Institute for Health and Care Excellence: High-sensitivity troponin tests for the early rule out of NSTEMI (HTG552), Evidence
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.