Iron deficiency is the most common cause of anaemia in the world. Despite frequently weak and masked clinical presentation of iron deficiency anaemia (IDA), this disease is very serious with complications leading to early mortality. In the developed countries IDA is predominantly diagnosed as the complication of another disease or as the result of major bleeding events. Diagnosis of IDA should be based on laboratory findings i. e. haemoglobin, mean corpuscular hemoglobin concentration and ferritin. Latter is the most sensitive marker for iron deficiency. Anaemia of chronic disease should be taken into an account as a potential differential diagnosis or coexisting state. For women in fertility age with IDA, gynaecological disorders should be ruled out first. Males and postmenopausal women with IDA should undergo upper, lower and in certain cases capsule endoscopy and/or enteroscopy to find a plausible cause of IDA. The ultimate goal of therapy is to find out and treat the primary cause of IDA. Iron body stores should be restored using either oral or parenteral iron preparations. The use of parenteral iron preparations in patients with gastrointestinal pathologies is often clinically substantiated for the treatment of IDA. Red blood cell transfusion should be administered in emergency cases only.
