Skip to main content

Health Encyclopedia

Search the Health Encyclopedia

Methylene blue test

Definition

The methylene blue test is a test to determine the type or to treat methemoglobinemia, a blood disorder.

Alternative Names

Methemoglobinemia - methylene blue test

How the Test is Performed

The health care provider wraps a tight band or blood pressure cuff around your upper arm. The pressure causes veins below the area to fill with blood.

The arm is cleaned with a germ killer (antiseptic). A needle is placed into your vein, usually near the inside of the elbow or back of the hand. A thin tube, called a catheter, is placed into the vein. (This may be called an IV, which means intravenous). While the tube stays in place, the needle and tourniquet are removed.

A dark green powder called methylene blue goes through the tube into your vein. The provider looks at how the powder turns a substance in the blood called methemoglobin into normal hemoglobin.

How to Prepare for the Test

No special preparation is required for this test.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

There are several types of oxygen-carrying proteins in the blood. One of them is methemoglobin. Normal methemoglobin level in blood are usually 1%. If the level is higher, you can become sick because the protein is not carrying oxygen. This can make your blood look brown instead of red.

Methemoglobinemia has several causes, many of which are genetic (problem with your genes). This test is used to tell the difference between methemoglobinemia caused by the lack of a protein called cytochrome b5 reductase and other types that are passed down through families (inherited). Your doctor will use the results of this test to help determine your treatment.

Normal Results

Normally, methylene blue quickly lowers the level of methemoglobin in the blood.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

You may have a rare form of methemoglobinemia if this test does not significantly lower the blood level of methemoglobin.

Risks

Veins and arteries vary in size from one person to another and from one side of the body to the other. Inserting an IV may be more difficult for you or your child than for other people.

Other risks associated with this type of blood test are minor, but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin causing bruising)
  • Infection (a slight risk any time the skin is broken, but the chances of infection increase the longer the IV remains in the vein)

References

Benz EJ Jr, Ebert BL. Hemoglobin variants associated with hemolytic anemia, altered oxygen affinity, and methemoglobinemias. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 41.

Chernecky CC, Berger BJ. Methemoglobin - blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:781-782.

Review Date:10/30/2016
Reviewed By:Anna C. Edens Hurst, MD, MS, Assistant Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

adam.com

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.

Health
Outcome Data

No data available for this condition/procedure.

Health Encyclopedia

More Features

We Appreciate Your Feedback!
1. Did you find this information useful?
         Yes
         No
2. Would you recommend this website to family and friends?
         Yes
         No