G6PD and G6PD deficiency: Unfortunately, G6PD markedly decreases with aging, which may lead to an increased morbidity rate in patients with COVID-19 infection.30 In addition, it is suggested that metabolic syndrome causes acquired G6PD deficiency and is involved in poor outcomes in COVID-19 patients.18 There is high prevalence of venous thromboembolic events in patients with COVID-19, which requires anticoagulation, therefore knowing the hemolytic status of patients is crucial.36