Hello, it is a skin disease that involves the oil glands at the base of hair follicles. It occurs during puberty. When male hormones produced by the adrenal glands of both females and males stimulate the sebaceous glands. These sebaceous glands have got spores and produce sebum. A small hair grows through the follicle and pimples grow when these follicles gets blocked. These pimples appear on face, back, chest, shadows and neck. There are different types of pimples like: whiteheads, black heads, papules, pustules, nodules and cysts. It affects all races and ages but is common between 11 to 30 years old. Men suffer from acne more than women because of testosterone, which is present in higher quantities in young men. Primary cause could be rise in androgen level. This androgen level rises when a person becomes adolescent. Sometimes genetics also play apart and even medications, which contain androgen and lithium and even greasy cosmetics too. Hormonal changes during pregnancy may cause acne. Treatment depends on whether it is mild or severe. If it is mild you can use Benzyl peroxide, Salicylic acid, Retina-A, Azelaic acid. In severe cases it is better to be treated by a dermatologist. The whole process depends on the severity of the infection like regular washing of face; application of ant acne cream or gel (if it is greasy) will do suffice. Sometimes you may have to take oral antibiotics also. In certain cases oral contraceptives suppress the overactive gland after checking with a gynecologist. As long as you do not meddle with the pimples, it gets cleared in course of time. In case if you start plucking these pimples, it may leave a scar, which is a bit difficult to take it out. Hence, in your case, it is the age, sexual activity, and hormonal disturbances or role-plays a part in that. I would suggest you to consult your dermatologist. Thank you.