Atypical Hemolytic Uremic Syndrome (aHUS) is a rare condition characterized by the destruction of red blood cells, low platelet counts, and kidney failure. It occurs due to uncontrolled activation of the complement system, a part of the immune system that helps fight infections. This uncontrolled activation can lead to damage in blood vessels, particularly in the kidneys. The symptoms of aHUS may include fatigue, pallor, and decreased urine output. Diagnosis typically involves blood tests and kidney function assessments. Treatment options may include plasma exchange, complement inhibitors, or supportive care to manage symptoms and prevent complications.