Autoimmune hemolytic anemia (AIHA)

Autoimmune hemolytic anemia affects the red blood cells. The immune system is thought to produce autoantibodies that attach to a person's own red blood cells and mark them for early destruction, a process called hemolysis, faster than the bone marrow can replace them.

Warm AIHA, in which the antibodies react best at body temperature, accounts for over two-thirds of cases and is the most common form, and it can occur on its own or alongside another condition such as lupus. AIHA is rare, with research describing a prevalence in the range of roughly 4 to 20 cases per 100,000 people depending on the population studied, and it becomes more common with age and occurs more often in women than men. Severity varies widely, and the destruction of red blood cells can happen gradually or quite quickly, which is part of why ongoing monitoring matters.

Common signs

Fatigue, weakness, pale or yellowish (jaundiced) skin, shortness of breath, a fast or pounding heartbeat, dizziness, dark urine, and sometimes an enlarged spleen or discomfort in the upper left abdomen.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.