The body is protected from infection by the immune system, which is a complex network of organs, cells, and proteins. The immune system of the body includes white blood cells. They support the body’s defences against illness and infection. Granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes (T cells and B cells) are different types of white blood cells.

They guard us from illness and disease. Think of white blood cells as your body’s defence mechanisms. They are, in a sense, always at war. They circulate through your circulation in order to fight off bacteria, viruses, and other harmful foreign invaders.

Blood typically contains 4,500 to 11,000 WBCs per microliter (4.5 to 11.0 109/L), or WBCs.