Certain medications: Corticosteroids, lithium, birth control with progesterone, testosterone, anticonvulsants, androgenic steroids, DHEA, barbiturates, and medicines that include bromides or iodides can cause acne or worsen it.
Excess sebum production: Sebum is a naturally occurring substance within the body that lubricates our skin and hair. The production of sebum is boosted during adolescence with hormonal changes, which often leads to breakouts.
Dead skin: Dead skin is a trigger for acne, and can accumulate as a result of junk food, stress, and not having a good skin care regimen.
Beauty products: Hair and skin products, as well as makeup, can clog pores and cause breakouts.
Clogged pores: When the pores become clogged with debris such as oil, bacteria, dirt, and dead skin, it often causes acne breakouts.
Blocked hair follicles: When hair follicles get blocked up by skin cells and sebum, it can create a follicular plug and inflammation.
Propionibacterium acnes: This is bacteria that lives on the skin and uses sebum for energy. When it overgrows, its presence in the pores triggers an immunity response that causes inflammation, and acne breakouts then often occur.
Genetics: The chances of you having problems with acne are much higher if one (or both) of your parents dealt with acne. This is because you may have inherited how their body deals with oil secretion.