Share this page
Print this article
Was this page helpful?

Myoglobin

Formal name: Myoglobin
Related tests: CK, CK-MB, Troponin

At a Glance

Why Get Tested?

To determine whether muscle, particularly heart muscle, has been injured

When to Get Tested?

Every 2–3 hours for the first several hours after experiencing chest pain that is suspected to be a heart attack

Sample Required?

A blood sample drawn from a vein in the arm

Test Preparation Needed?

None

The Test Sample

What is being tested?

Blood is being tested for the presence of myoglobin, which is a protein found in heart and other muscles. While haemoglobin brings oxygen to most of the body, myoglobin traps oxygen in muscle to allow muscle cells to work properly. When heart or other muscle is injured, myoglobin is released into the blood.

How is the sample collected for testing?

A blood sample is taken by needle from a vein in the arm.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

How is it used?

Myoglobin is a small protein, and it leaks out of cells soon after injury. Myoglobin levels start to rise within 1–3 hours of a heart attack or other muscle injury, reach their highest values by about 8–12 hours, and generally fall back to normal by about one day after injury occurred.

^ Back to top

When is it requested?

Myoglobin tests may be used in people with chest pain who are suspected of having had a heart attack, particularly if the electrocardiogram (ECG) does not give clear cut results. (The ECG records the electrical changes in different parts of the heart muscle as it beats; the patterns change when heart muscle is damaged. Myoglobin is not widely used for diagnosing heart attacks because troponin is much more specific.

^ Back to top

What does the test result mean?

Looking for reference ranges?

When myoglobin rises, there has been very recent injury to the heart or other muscle tissue. If myoglobin does not increase at that point, a heart attack is very unlikely, unless the chest pain started more than a day before.

Because myoglobin is also found in other muscles, high levels usually require using other tests (such as CK–MB or troponin) to tell whether the damage was to heart or to other muscle. High levels can occur in accidents, fits, surgery or any muscle disease.

^ Back to top

Is there anything else I should know?

Increased myoglobin levels can occur after injections into muscles or strenuous exercise. Because the kidneys remove myoglobin from the blood, myoglobin levels may be high in persons whose kidneys are failing. Rarely, heavy alcohol abuse and certain drugs can cause muscle injury and increase myoglobin.

^ Back to top

Common Questions

1.  What does heart attack mean?

Heart attack means that some of the muscle in your heart has died. A medical term for this is myocardial infarction. Most commonly, a heart attack starts with a kind of heavy pressure or pain in the chest, often extending into the neck or left arm. You may have trouble catching your breath, or you may feel weak and break into a cold sweat.

A heart attack usually occurs because one of the blood vessels (called coronary arteries) that bring blood to your heart muscle is blocked. This usually happens when a blood clot forms in a blood vessel that is already partially blocked. The partial blockage, which happens gradually over many years, is usually caused by too much fat layered in the wall of the blood vessel (this is often called hardening of the arteries — the medical term for this is atherosclerosis).

^ Back to top

2.  If I have chest pain, does that mean I am having a heart attack?

Many other problems can cause chest pain, and it is not always possible to tell just from the type of chest pain whether or not you are having a heart attack. Many people have chest pain from straining the muscles in their chest and chest pain can occur with some lung problems. Chest pain can be a warning sign of hardening of the arteries of the heart (coronary artery disease or CAD).

Chest pain that occurs during exercise, hard work or at times of stress, lasts for a few minutes and goes away with rest is called angina. If the pain lasts longer than just a few minutes, especially if it occurs when you are resting, seek immediate medical attention.

^ Back to top

3.  What are the other heart attack tests?

Doctors often use more than one laboratory test as well as an ECG to determine if a person who has chest pain is having a heart attack. Troponin can pick up damage to heart muscles even when there is no other evidence of a heart attack.

^ Back to top

4.  What if I’m not sure I’m having a heart attack?

If you have prolonged chest pain, especially if it does not go away with rest — or if you have been told you have angina, and the drugs you were prescribed do not ease the pain, seek immediate medical attention. Many people who have had a heart attack die without ever having tried to call an ambulance or to get to an emergency room.

^ Back to top

5.  Is myoglobin useful to evaluate a stroke, too?

A stroke occurs when part of the brain dies. Like a heart attack, it usually is due to a blockage of one of the blood vessels that brings blood to the brain. Myoglobin is only found in muscle cells, not in the brain, so it is not helpful in evaluating a person who may have had a stroke.

^ Back to top

Ask a Laboratory Scientist

* indicates a required field!




  Patient, Family member or Friend
  Healthcare Professional
  Other



You must provide a valid email address in order to receive a response.




Spam Prevention

| |

Article Sources

« Return to Related Pages

NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.