What Is Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency?

Medically Reviewed by Dan Brennan, MD on June 08, 2021

Glucose-6-phosphate dehydrogenase deficiency, also known as G6PD deficiency, is a common genetic condition. It’s the most frequently occurring enzyme deficiency, affecting about 400 million people in the world.

The deficiency is inherited and affects an enzyme that is important for the health of your red blood cells. G6PD fuels red blood cells and shields them from harmful substances found in the blood. If you are deficient, your body doesn’t produce enough of the G6PD enzyme, or the G6PD it does create is not effective.

If you have G6PD deficiency, you do not need treatment, but you should avoid certain drugs, chemicals, and beans to manage your G6PD deficiency. If left alone, your G6PD deficiency could result in some serious side effects; one of the most damaging is hemolytic anemia.

A simple blood test performed by your doctor can inform you if you have G6PD deficiency. 


Glucose-6-phosphate dehydrogenase deficiency doesn’t usually have symptoms. There are more than 300 variants of G6PD deficiency, so symptoms may vary according to the unique kind of deficiency you have. Different variations have higher levels of insufficient G6PD enzymes and are more serious than others.

In newborn babies, G6PD deficiency can show up as jaundiced, or yellowed, skin that is easily fixable. In anyone with G6PD, whether you’re anemic or not, you could experience hemolytic anemia if you get an infection or take a certain medication. 

Hemolytic anemia is a condition wherein your red blood cells are damaged faster than they are created. Because you need your red blood cells to bring oxygen to every part of your body, getting hemolytic anemia means your body isn’t getting enough oxygen. Symptoms of this dangerous side effect include:

  • Pale or colorless skin
  • Jaundiced skin
  • Dark urine
  • Fever
  • Weakened physical state
  • Disorientation
  • High heart rate

Hemolytic anemia could be life-threatening, depending on how severely you suffer from it. Contact your healthcare provider if you experience severe symptoms for an extended period of time. Otherwise, it may resolve itself within two weeks. If you end up developing chronic hemolytic anemia, ask your doctor about the benefits of folic acid supplements.


Glucose-6-phosphate dehydrogenase deficiency is hereditary, so you can’t “catch” it, and you won’t develop it by chance. There are no avoidable causes, but you can get tested or be on the lookout for symptoms if you fall into a group that is more likely to have G6PD:

  • Males
  • People of African descent
  • People of Asian descent
  • People of Mediterranean descent
  • People of Middle-Eastern descent


If you have a family history of glucose-6-phosphate dehydrogenase, your doctor might ask you if you want to be screened. If your screening results are positive, you’ll move on to quantitative testing. The Beutler test, or the fluorescent spot test, is a semi-quantitative test. Semi-quantitative tests detect the presence of G6PD deficiency. If you test positive, your blood will show up fluorescent under a UV light.

The Beutler test is only reliable when diagnosing males, so your doctor will perform a different analysis if you’re a female. You could undergo any of the following:

  • Spectrophotometric analysis. This method includes shining light through a blood sample to see how much light passes through and how much is absorbed.
  • Rapid point-of-care diagnostic test. A qualitative test that determines if a blood sample has characteristics of G6PD deficiency. It delivers quick results.

Living with G6PD

If you test positive for glucose-6-phosphate dehydrogenase deficiency, you don’t need treatment. Learn what irritates your G6PD deficiency, and learn the warning signs for hemolytic anemia. At the top of your list will be avoiding certain medications and chemicals that lead to oxidative stress, including:

  • Aspirin
  • Phenazopyridine (urinary pain relief)
  • Rasburicase (uric acid cleanser)
  • Antibiotics that have “sulf” as part of their name
  • Anti-malaria medications that have “quine” as part of their name
  • Fava beans 
  • Naphthalene (found in mothballs)

Oxidative stress is defined as an excess of harmful cells and not enough antioxidants to disable them. If you don’t get a handle on your oxidative stress, you could end up developing certain diseases and aging quickly.

If you know your family has a history of glucose-6-phosphate dehydrogenase deficiency, contact your doctor to find out if you should be screened or tested. Although it is often a minor condition, the knowledge of a positive or negative test could help you avoid unwanted side effects.

WebMD Medical Reference



American Family Physician: “Diagnosis and Management of G6PD Deficiency.”

Johns Hopkins Medicine: “Hemolytic Anemia.”

KidsHealth: “G6PD Deficiency.”

Lab Tests Online: “G6PD.”

Medscape: “Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency Workup.”

Oxidative medicine and cellular longevity: “Oxidative Stress: Harms and Benefits for Human Health.”

University of Rochester Medical Center: “Glucose-6-Phosphate Dehydrogenase.”

© 2020 WebMD, LLC. All rights reserved.