Anemia is the world’s most common blood disorder
It affects roughly one-fifth to one-third of people globally. Iron deficiency alone touches nearly a billion, and hemoglobin cutoffs differ by sex and pregnancy—under 130 g/L for men, under 120 for non-pregnant women.
Anemia means blood that cannot carry enough oxygen—too few red cells, too little hemoglobin, or hemoglobin that works poorly. Slow-onset cases feel like tiredness, weakness, breathlessness, headaches, and poor exercise tolerance; acute drops bring confusion, near-fainting, thirst, and collapse. Noticeable pallor usually requires significant disease. Causes cluster into blood loss (menstruation, gut bleeding, surgery, trauma, donation), underproduction (iron, folate, or B12 lack, thalassemia, marrow tumors), and excess breakdown (sickle cell disease, malaria, autoimmune hemolysis).
Labs classify by cell size—microcytic, normocytic, or macrocytic—and by hemoglobin thresholds: under 130 g/L in men, under 120 in non-pregnant women, and under about 105–110 in pregnancy. Iron-deficiency anemia is the leading global cause; anemia overall is the most common blood disorder, hitting about a fifth to a third of humanity. In 2013 iron-deficiency anemia caused roughly 183,000 deaths, down from about 213,000 in 1990. Prevalence among women aged 15–49 rose from 27.6 to 30.7 percent between 2012 and 2023 in global tracking, with little regional improvement. WHO lists anemia among its 2025 nutrition targets and links progress to Sustainable Development Goal 2.
Treatment follows cause. Iron pills can prevent problems in groups such as pregnant women, but blind dietary supplements without a diagnosis are not recommended. Transfusions usually track symptoms; in people without symptoms they are typically withheld unless hemoglobin falls below about 60–80 g/L. Erythropoiesis-stimulating agents are reserved for severe anemia. Chronic iron lack may bring spoon nails, a smooth sore tongue, hair loss, or pica; B12 deficiency can add anxiety, confusion, memory loss, and depression. Infants with chronic anemia risk poor growth and impaired neurological development. The Greek roots say “not blood,” but the modern problem is oxygen delivery gone wrong.
Source: Anemia
