Iron deficiency anemia may be caused by insufficient iron intake, impaired iron absorption and excessive iron loss. 1. Insufficient iron intake: children’s developmental period, puberty, pregnant women, breastfeeding, etc. will increase the consumption of iron. If you are not able to supplement high iron foods, it will easily lead to iron deficiency anemia. 2. Iron absorption obstacles: for example, patients with atrophic gastritis or gastric resection, due to the lack of gastric acid can lead to iron absorption obstacles, causing iron deficiency anemia. 3. Excessive iron loss: long-term chronic iron loss is not timely corrected, it is easy to lead to iron deficiency anemia. For example, chronic gastrointestinal blood loss, gastric ulcer bleeding, gastrointestinal tumors, parasitic infections, etc., can lead to excessive iron loss, thus causing iron deficiency anemia. If patients are found to have iron deficiency anemia, they should eat more lean meat, animal liver and other iron-rich foods in their life, and clarify the cause of the disease under the guidance of doctors for targeted treatment.