Our immune system protects us from infection by pathogens such as bacteria, viruses, and parasites. It also protects us from cancer and restores damaged tissue.
Although we are born with the foundation of an immune system, the majority of our immunity is acquired through exposure to various pathogens as we age. A healthy immune system learns to distinguish these pathogens from body’s own tissues, but when things go awry, the immune system attacks body tissues, a phenomenon referred to as autoimmune disease.
