Although the exact cause of acne is unknown, many doctors believe is a direct result of a variety of factors. One such factor is the increase in androgens during puberty. Androgens are hormones, and can cause the enlargement and overstimulation of the sebaceous glands in people with acne.

For both men and women, the increase in androgens during puberty can cause these sebaceous glands produce more sebum, which is oil. This oil mixes with dead skin cells and bacteria on the skin and blocks pores. Within these blocked pores bacteria multiplies and leads to swelling, causing blemishes and pimples.

Some researchers also believe that acne is hereditary, and that people with parents who had acne are likely to inherit acne.

Although stress was not found to be a direct cause of acne, which can lead to aggravated cases of acne. This happens because when someone is charged with anxiety, your body produces hormones such as cortisol, which exacerbates acne.

Other possible causes of acne include certain medications, drugs, steroids, have oily or makeup, and cleaning the hard skin.

Greasy food and dirty skin have often been blamed for acne but there is little evidence to support these direct causes of acne. Acne is not contagious.