How to approach haemolysis: Haemolytic anaemia for the general physician.

Haemolytic anaemia can seem like a complicated topic. The constellation of reticulocytosis, increased lactate dehydrogenase levels, increased unconjugated bilirubin levels and decreased haptoglobin levels should prompt general physicians to consider haemolysis as a differential diagnosis. When further approaching haemolytic anaemia, subdividing patients into those who are 'direct antiglobulin test (DAT) positive' (immune) or 'DAT negative' (non-immune) is a simple and clinically relevant way to start to formulate a cause for the haemolytic anaemia. Immune causes of haemolytic anaemia include autoimmune haemolytic anaemia, drugs and delayed haemolytic transfusion reactions. Non-immune causes include the haemoglobinopathies (such as sickle cell disease) and microangiopathic haemolytic anaemias (such as disseminated intravascular coagulation). Early supportive care in haemolytic anaemia is important and may involve blood transfusions as well as interventions to slow the rate of haemolysis, such as steroids in autoimmune haemolytic anaemia. Complications of haemolysis include pigment gallstones, high-output cardiac failure and thromboembolism. Haemolytic anaemia should be referred to the haematologist for further investigation, however, the recognition and early management by the general physician is imperative in improving the patient's outcome. © Royal College of Physicians 2022. All rights reserved.