The Purpose of Himoglobin Testing

The Purpose of Testing

You acquire different abnormal types of hemoglobin by inheriting the genes that produce them. Your doctor may recommend a hemoglobin electrophoresis test to determine if you have a disease that causes the production of abnormal hemoglobin, such as the following.

Sickle Cell Anemia

This disorder is caused by hemoglobin S. Red blood cells become hard and crescent-shaped. They block small blood vessels and prevent blood from circulating properly.

Thalassemias

These genetic disorders can cause the production of too much abnormal hemoglobin and too little hemoglobin A.

Testing Children

Your doctor may also want to test your child if you have a family history of abnormal hemoglobin or they have anemia that’s not caused by an iron deficiency.

Part 3 of 6: Administration

Where and How the Test Is Administered

No special preparations are required for this test.

Your doctor will need to take a sample of blood from your arm or hand. They’ll clean the site with a swab of rubbing alcohol. Then they’ll insert a small needle with a tube attached to collect the blood. When enough blood has been drawn, they’ll remove the needle and cover the site with a gauze pad. They’ll send your blood sample to a laboratory for analysis.

In the laboratory, a process called electrophoresis passes an electrical current through the hemoglobin in your blood sample. This causes the different types of hemoglobin to separate into different bands. Your blood sample is then compared to a healthy sample to determine which types of hemoglobin are present.

Part 4 of 6: Results

Understanding the Results

Normal Results

The following are healthy levels of hemoglobin in infants and children.

• hemoglobin F (newborn): 50 to 80 percent
• hemoglobin F (6 months): 8 percent
• hemoglobin F (6 months+): 0.8 to 2 percent

The following are healthy levels of hemoglobin in adults.

• hemoglobin A: 95 to 98 percent
• hemoglobin A2: 2 to 3 percent
• hemoglobin F: 0.8 to 2 percent
• hemoglobin S: 0 percent
• hemoglobin C: 0 percent

Abnormal Results

If your results show abnormal hemoglobin levels, they may be caused by:

• hemoglobin C disease (a genetic disorder that leads to severe anemia)
• rare hemoglobinopathy (a group of genetic disorders causing the abnormal production or structure of red blood cells)
• sickle cell anemia
• thalassemia

Part 5 of 6: Risks

What Are the Risks of the Test?

As with any blood test, there are minimal risks of bruising, bleeding, or infection at the puncture site. In rare cases, the vein may swell after blood is drawn. This condition, known as phlebitis, can be treated with a warm compress several times a day. Ongoing bleeding could be a problem if you have a bleeding disorder or are taking blood-thinning medication, such as warfarin (Coumadin) or aspirin.