Acne is a result of hair follicles being obstructed by dead skin and oil. This happens when sebum, an oily substance that is secreted by sebaceous glands, is produced in excess amounts. Sebum combined with dead skin cells forms a soft plug in the follicle. There, the skin bacteria cause an infection whereby pustule and cysts are created.
Acne is typically caused by testosterone. During puberty, the body of a teenager produces increased levels of testosterone. In turn, this triggers the excessive secretion of sebum because sebaceous glands are particularly sensitive to hormones. This excess sebum, which normally travels up the hair shafts to lubricate a person’s hair and skin, leads to inflammation and the creation of painful red spots known as pimples.
Having a parent who suffered acne during puberty or who is suffering from acne as an adult indicates a high risk of the child developing the same problem. In addition to its hereditary causes, acne can be caused by certain cosmetic products, especially if a person has sensitive skin. Medications such as lithium and anti-epileptic drugs can also lead to acne development. Stress is also a factor because it exacerbates the acne problem, even though it doesn't cause it directly.
Women are more likely to suffer from adult-onset acne. The changes in the hormone levels during pregnancy or just before periods are typically the main cause behind the problem.