G6PD deficiency is a common enzyme deficiency affecting approximately 400 million people worldwide. It is caused by mutations in the G6PD gene located on the X chromosome, making males more likely to be affected. G6PD deficiency results in hemolytic anemia when red blood cells are exposed to oxidative agents found in certain drugs or foods like fava beans. A complete blood count or screening test can diagnose G6PD deficiency by measuring enzyme activity levels in the blood. Current treatment involves avoiding triggers like fava beans and oxidative drugs that can cause hemolysis in G6PD deficient individuals.