What is a troponin test?

A troponin test measures the level of troponin in a sample of your blood. Troponin is a protein that's found in the cells of your heart muscle.

Normally, troponin levels in blood are so low that only the most sensitive types of tests can measure them. But if your heart muscle is damaged, troponin leaks into your bloodstream, and your troponin blood levels will rise.

Troponin testing is mainly used to help diagnose heart attacks. Heart attacks damage the heart by suddenly blocking the blood flow that brings oxygen to part of the heart muscle. Without oxygen from blood, heart muscle cells die and release troponin.

Troponin test results can confirm damage to the heart muscle from a heart attack. The more damage there is to the heart, the more troponin is released into the blood. So, measuring the amount of troponin in the blood can also help estimate how much of the heart has been damaged. Higher than normal troponin levels may also be found in other conditions that can damage heart muscle.

Two types of troponin maybe be measured to diagnose heart damage. They are called troponin I and troponin T. Tests can measure either type.

Other names: cardiac troponin I (cTnI), cardiac troponin T (cTnT), cardiac troponin (cTn), cardiac-specific troponin I and troponin T

What is it used for?

A troponin test is mainly used to:

• Confirm if a person is having a heart attack or recently had a heart attack. This is the most common reason for troponin testing. The test is usually done in the emergency room of a hospital along with other heart tests, such as an EKG (also called an ECG or electrocardiogram).
• Diagnose and monitor unstable angina. Angina is chest pain that happens if part of the heart muscle doesn't get as much blood as it needs. Unstable angina is a type of angina that happens at any time, even during rest. It's a medical emergency because it can lead to a heart attack.
• Check heart health after a surgery that could damage the heart. In this case, a troponin test may be done before and after surgery so that the results can be compared.

Why do I need a troponin test?

You may need a troponin test if you have symptoms of a heart attack. The symptoms can start slowly or suddenly. They may be mild or intense, and they can come and go over several hours. They include:

• Chest pain, heaviness, or discomfort in the center or left side of the chest
• Pain or discomfort in one or both arms, your back, shoulders, neck, jaw, or above your belly button
• Trouble breathing when resting or doing light physical activity
• Nausea and vomiting
• Feeling unusually tired for no reason, sometimes for days
• Dizziness and light-headedness
• Sweating a lot for no reason
• Rapid or irregular heartbeat (arrhythmia)

If you have symptoms of a heart attack, call 911 immediately. Quick medical attention could save your life.

You may also need troponin testing if you're having surgery that could affect your heart.

What happens during a troponin test?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a troponin test. But, if you take vitamin B7, also called biotin, make sure you tell the health care provider who orders your test. Biotin and supplements that contain biotin can make your troponin levels appear lower than they really are.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

To understand the results of a troponin test for chest pain and/or other symptoms of a heart attack, your provider will consider your symptoms, medical history, and the results of other tests.

In general:

• If your first troponin test results are normal, you'll probably be retested during the next 12 hours. That's because increased troponin levels usually don't show up for about 2 to 3 hours after a heart attack begins. So, results from a later test may show higher than normal troponin levels. In the meantime, the results of other tests and exams will help your provider know whether to start treatment for a heart attack right away.
• If your troponin test results show normal troponin levels 12 hours after your symptoms began, you probably did not have a heart attack.
• If your test results show higher than normal amounts of troponin in your blood, it usually means you have some damage in your heart muscle. Your provider will consider all the information about your condition to diagnose whether a heart attack caused the damage. Very high troponin levels most often mean you've had a heart attack.

Higher than normal troponin levels don't always mean you've had a heart attack. They can be caused by unstable angina many other conditions that can damage the heart, including:

• Irregular heartbeat (arrhythmia), especially a heartbeat that's too fast
• Heart failure
• Heart valve disease
• Infection or inflammation of the heart muscle (myocarditis)
• Heart surgery
• Intense exercise over a long time, such as running a marathon
• Chest injuries
• Chronic kidney disease
• A blood clot in your lungs (pulmonary embolism)
• Sepsis
• A severe COVID-19 infection

If you have high troponin levels, but your provider doesn't think you've had a heart attack, you may have other tests to find the cause.

If you have questions about your test results, talk with your provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a troponin test?

Troponin levels can continue to rise for about 24 hours after a heart attack begins. So, if your test results show high troponin levels, you'll probably be tested two or more times over a 24-hour period.

The results of these tests show how fast your troponin level increased and the highest level it reached. That information helps estimate how much of your heart muscle is damaged and how well you might recover.