What is a G6PD test?

This test measures the amount of G6PD in the blood. G6PD stands for glucose-6-phosphate dehydrogenase, an enzyme that helps red blood cells work properly. Red blood cells move oxygen from your lungs to every cell in your body. Your cells need oxygen to grow, reproduce, and stay healthy.

If you don’t have enough G6PD, it’s known as G6PD deficiency. This is a genetic disorder that mostly affects males. G6PD deficiency can cause the destruction of red blood cells. When red blood cells are destroyed faster than the body can replace them, it’s called hemolytic anemia. If you have hemolytic anemia, your cells don’t get all the oxygen they need.

Most people with G6PD deficiency don’t have symptoms of disease until they are exposed to certain “triggers,” which set off the destruction of red blood cells. Triggers include:

  • Fava beans, also called broad beans
  • Viral infections
  • Bacterial infections
  • Certain antibiotics
  • Anti-malaria medicines
  • Other medicines, including nonsteroidal, anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin

Other names: G6PD deficiency test, glucose-6-phosphate dehydrogenase test

What is it used for?

A G6PD test is used to check for a G6PD deficiency (not enough G6PD).

Why do I need a G6PD test?

You may need a G6PD test if you have symptoms of hemolytic anemia. These include:

  • Fatigue
  • Pale skin or jaundice, a condition that causes your skin and eyes to turn yellow
  • Rapid heart rate
  • Shortness of breath
  • Dark or yellow-orange colored urine

Your newborn baby might need a G6PD test if he or she has jaundice that doesn’t go away in two weeks and/or is not explained by another condition. Your baby may also be tested if you have a family history of G6PD deficiency.

What happens during a G6PD 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.

If your baby is being tested, a health care provider will clean your baby’s heel with alcohol and poke the heel with a small needle. The provider will collect a few drops of blood and put a bandage on the site.

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

There are no special preparations needed for a G6PD test.

Are there any risks to this 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.

Your baby may feel a little pinch when the heel is poked, and a small bruise may form at the site. This should go away quickly.

What do the results mean?

If your results show you have lower than normal amounts of G6PD, it means you have a G6PD deficiency. But your symptoms and risk of getting hemolytic anemia can vary depending on your personal health history and exposure to triggers.

Women who have slightly lower than normal amounts of G6PD may be “carriers” of a G6PD deficiency. That means they have one defective G6PD gene and one normal G6PD gene. These women rarely have symptoms, as their normal G6PD genes usually make enough healthy red blood cells. But they have a risk of passing on the defective gene to their children. Male children are more likely to develop G6PD symptoms than female children.