Atypical Hemolytic Uremic Syndrome (aHUS)

Understanding Atypical Hemolytic Uremic Syndrome (aHUS)

Atypical Hemolytic Uremic Syndrome (aHUS) is a rare, life-threatening disease characterized by uncontrolled activation of the complement system, which leads to the formation of blood clots in small blood vessels (thrombotic microangiopathy, TMA). This process results in hemolytic anemia (the destruction of red blood cells), thrombocytopenia (a low platelet count), and kidney failure. Unlike typical HUS—often triggered by infections such as E. coli— aHUS is primarily genetic or immune-mediated and can be precipitated by factors such as infections, pregnancy, surgery, or certain medications.

Common Signs and Symptoms of aHUS:

• Hemolytic Anemia:
  • Fatigue, pallor, and shortness of breath due to the destruction of red blood cells.
• Thrombocytopenia:
  • Easy bruising, prolonged bleeding from cuts, or petechiae (small red or purple spots on the skin).
• Kidney Dysfunction:
  • Reduced urine output, swelling (edema), or signs of kidney failure.
• General Symptoms:
  • Abdominal pain, headache, or confusion that may result from reduced blood flow or the systemic effects of microthrombi.

This information is provided as a resource and is not intended to diagnose a condition or prescribe treatment. Please discuss any symptoms you may exhibit with your physician.