Chronic inflammation in hemodialysis patients (micro-inflammation) is caused by multiple inflammatory stimuli and becomes apparent by elevated levels of biochemical markers such as CRP, IL-6, cellular activation markers etc. Chronic inflammation is linked to clinical signs and symptoms and cardiovascular mortality in dialysis patients. Inflamed dialysis patients show impaired response to erythropoiesis-stimulating agents (ESA) related to reduced iron utilization (functional iron deficiency) and elevated CRP levels are associated with a greater need for ESA to meet hemoglobin targets. If absolute iron deficiency can been excluded, EPO resistance is likely related to 'inflammatory block'.