The treatment of iron deficiency anemia mainly includes two aspects: one is iron supplementation, and the other is identifying and correcting the underlying cause of the anemia. Iron supplementation for patients with iron deficiency anemia can be administered orally or via intravenous infusion, the latter of which tends to be faster. Generally, hemoglobin begins to rise about a week after treatment starts, and returns to normal levels within two to three weeks. Even after hemoglobin levels normalize, iron supplementation should continue for three to six months. It is more important to identify and treat the underlying causes of anemia. Common causes of iron deficiency anemia include chronic blood loss, such as from gastrointestinal ulcers or tumors. Therefore, patients with iron deficiency anemia typically need to undergo gastrointestinal endoscopy to identify the specific cause of the iron deficiency.