What causes acne?

The sebaceous glands are located just under the skin surface and keep the skin supple and smooth by producing oil (sebum). The oil is transported to the skin surface through the pores. The pores are also connected to the hair follicle. In the teenage years, the glands start to produce increased levels of sebum due to hormonal changes. The excessive production of sebum clogs the pores. Dead skin cells and bacteria that are usually carried with the oil to the surface become encapsulated in the follicles and inflammation occurs.