There are four major factors responsible for causing acne. They act together to cause the characteristic pimples, whiteheads and blackheads associated with acne. There are:

Overactive oil glands

Blockage of the skin pores

Activity of normal skin bacteria

Inflammation

The process by which a pimple develops is highly intricate. While we do know that a pore collapses on itself and blocks serbum (oil) from escaping, we do not fully understand why this process takes place in one sebaceous gland versus another.