A blood transfusion may be used to treat severe anemia, especially when symptoms like chest pain, shortness of breath, dizziness, or extreme fatigue are present, or when hemoglobin levels are dangerously low. It works by giving healthy red blood cells from a donor to quickly restore oxygen-carrying capacity. Transfusions provide rapid relief of symptoms but are generally reserved for urgent situations rather than long-term management. Risks include allergic reactions, fever, iron overload, or, rarely, infections, so transfusions are carefully matched and monitored. Afterward, treatment of the underlying cause of anemia (such as iron or vitamin deficiency) is still necessary.