What is pus?

Pus is a thick, whitish-yellow fluid that oozes from a cut because white blood cells, bacteria, and dead skin cells have accumulated there. Eventually the white blood cells eat up all the bacteria and dead skin cells and the puss clears up on its own. Sometimes antibiotics are needed to kill off bacteria and help the wound heal more quickly. If a pimple gets infected with bacteria, the result is a pustule, or small amount of pus.