How does blood help fight infection?

Anthony L. Komaroff, MD

Internal Medicine

Blood participates in innate immunity. Proteins known as complement proteins circulate in the blood, coating invading bugs and punching holes in them, which speedily destroys them. Small fragments of complement proteins also adhere to the pathogen surface, flagging them for destruction by phagocytes.

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Blood Basics

Our blood is a living tissue with a variety of critical functions: It delivers oxygen and nutrients to our organs, fights infections and creates blood clots, preventing us from bleeding excessively when a blood vessel is damaged. The liquid part of our blood, called plasma, is key for maintaining blood pressure and supplying critical proteins for blood clotting, immunity and maintaining the correct pH balance in our body -- critical to cell function. Plasma also carries the solid part of our blood -- white blood cells, which work to destroy viruses and bacteria; red blood cells, which carry oxygen through the body; and platelets, which help clotting. Learn more about blood basics with expert advice from Sharecare.

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