Mast cells are a type of white blood cell - together, our white blood cells play a major role in our immune system, helping us fight off infection and other invaders. Mast cells are packed with histamine, a chemical released when you have an allergic reaction. They also contain heparin, a chemical which stops the blood from clotting. Mast cells are hard-working cells that have many functions, including helping to fight infection and healing wounds.
This is a companion discussion topic for the original article at https://patient.info/allergies-blood-immune/mastocytosis-and-mast-cell-disorders-leaflet