Anemia is one of the most common hematologic problems in childhood. In many children, particularly infants and adolescents, iron deficiency is an important and treatable cause. However, not every child with anemia has iron deficiency.
Anemia can result from inadequate iron intake, blood loss, inherited disorders, destruction of red blood cells, chronic inflammation, nutritional deficiencies, or disorders affecting the bone marrow. For this reason, the correct approach is not simply to prescribe iron whenever a child's hemoglobin is low. The first step is to understand why the child is anemic.
The American Academy of Pediatrics published an updated clinical report in 2026 addressing prevention, screening, diagnosis, and treatment of iron deficiency and iron-deficiency anemia from infancy through adolescence. The recommendations emphasize clinical risk factors, appropriate laboratory evaluation, and reassessment of children who have recurrent or treatment-resistant anemia.
Anemia occurs when the hemoglobin concentration is lower than expected for a child's age and physiologic characteristics. Hemoglobin is the protein in red blood cells responsible for carrying oxygen to tissues. Because normal hemoglobin values change throughout childhood, anemia should always be interpreted using age-appropriate reference ranges rather than a single universal cutoff.
Iron is essential for hemoglobin production, cellular metabolism, and normal neurodevelopment. Iron deficiency can occur before anemia develops. This is particularly important during infancy and adolescence, when iron requirements are increased. Iron deficiency has also been associated with impaired neurocognitive development.
Risk factors include:
Anemia has three main causes:
Decreased red blood cells or hemoglobin levels may be due to:
Risk factors for anemia include:
Most symptoms of anemia are due to the lack of oxygen in the cells. Many of the symptoms don't occur with mild anemia.
These are the most common symptoms:
Many of these symptoms may be caused by other blood problems or health conditions. Anemia is often a symptom of another disease. Report any symptoms to your child’s healthcare provider. Always see your child's provider for a diagnosis.
A complete blood count provides much more information than hemoglobin alone.
The pediatrician or hematologist may evaluate:
These findings help classify anemia as microcytic, normocytic, or macrocytic and provide important clues about its underlying mechanism.
Reticulocytes are newly produced red blood cells. The reticulocyte count helps determine whether the bone marrow is responding appropriately to anemia. A high reticulocyte response may occur when red blood cells are being destroyed or lost and the bone marrow is compensating. A low or inappropriately normal response may suggest inadequate red-cell production. This distinction can significantly narrow the differential diagnosis.
Depending on the clinical situation, evaluation may include:
Ferritin reflects iron stores but can increase during inflammation. Therefore, iron studies should be interpreted together with the child's clinical history and other laboratory findings. The 2026 AAP report emphasizes using clinical risk factors and appropriate laboratory testing rather than relying on a single laboratory value.
When the clinical picture strongly suggests iron deficiency, oral iron therapy may be appropriate.
However, the child's response should be monitored.
Failure to respond appropriately should therefore lead to reassessment rather than indefinite continuation of iron therapy.
Heavy menstrual bleeding is an important and sometimes overlooked cause of iron deficiency in adolescents.
Warning features include:
Iron deficiency may result from menstrual blood loss, but heavy menstrual bleeding can also be the first manifestation of an inherited bleeding disorder such as von Willebrand disease. A hematologic evaluation may therefore be necessary.
Further evaluation is particularly important when:
Anemia accompanied by abnormalities in white blood cells or platelets deserves particular attention because it may indicate a broader bone marrow disorder.
This is an important message for parents. Most children with anemia do not have leukemia or another cancer. Iron deficiency, inherited hemoglobin disorders, blood loss, and other conditions are much more common explanations. However, pediatric hematology is not simply about identifying cancer. It is about accurately determining the cause of an abnormal blood count and ensuring that children receive the appropriate treatment.
Specialist evaluation may be appropriate for children with:
The Bottom Line: If your child has been diagnosed with anemia, the most important question is not simply: “Which iron supplement should we give?”
It is: “Why is my child anemic?” For many children, the answer will be iron deficiency, which is usually treatable. But severe, persistent, recurrent, or unexplained anemia deserves a more detailed evaluation.
Early assessment can establish the correct diagnosis, prevent unnecessary treatment, and identify children who require specialist care.
