There are many misconceptions and rumors about acne. Exactly why some people get acne and some do not is not fully known. It is known to be partly hereditary. Several factors are known to be linked to acne symptons:

Family history
Hormonal activity, such as menstrual cycles and puberty
Stress, through increased output of hormones from the adrenal (stress) glands.
Hyperactive sebaceous glands, secondary to the three hormone sources above.
Accumulation of dead skin cells.
Bacteria in the pores, to which the body becomes 'allergic'.
Skin irritation or scratching of any sort will activate inflammation.
Use of anabolic steroids.
Any medication containing halogens (iodides, chlorides, bromides), lithium, barbiturates, or androgens.
Exposure to high levels of chlorine compounds, particularly chlorinated dioxins, can cause severe, long-lasting acne, known as Chloracne.

There is no widely agreed-upon proof that diet has any effect on most people's acne. Eating greasy foods may get grease on a person's hands: subsequent contact of the hands to the face may exacerbate acne.

Common myths state that masturbation causes acne and, conversely, that celibacy or sexual intercourse can cure it. Sexual activity can lead to hormonal surges and can also serve to relieve stress caused by inactivity or lack of self-confidence, more common in acne sufferers. Healthy sexual activity may improve the psychosomatic metabolism and mental maturity of an individual, but has not been scientifically correlated with changes in acne. Serious levels of inactivity combined with any serious levels of sexual stress worsen an individual's metabolism