Why Does Hard Pus Come out of Pimples?

Pimple pus is made from sebum (oil) that gets trapped in your pores, along with a combination of dead skin cells, debris (such as makeup), and bacteria. When you have inflammatory acne lesions (such as pustules, papules, nodules, and cysts), your immune system activates in this area, resulting in noticeable pus.

What is that hard white core in a pimple?

Pustules are what most people think of as a zit: Red and inflamed with a white head at the center. The stuff you squeeze out of them is pus, which contains dead white blood cells.

When I pop a pimple something hard comes out?

One common type is called a pustule. This is the kind with a red or pink inflamed border and a yellow or white center. As the name implies, pustules contain pus. This is the substance that comes out when you pop a pimple.