Some of the factors causing acne are:

- genetic history
- hormonal activity, such as puberty and menstrual cycle. This is the reason most teenagers, both male and female, develop acne.
- Stress, as increased amounts of hormones are released through the adrenal glands
- Hyperactive sebaceous glands, producing more sebum than what is naturally needed by the skin
- Accumulation of dead skin cells, blocking the pores
- Presence of bacteria in the pores
- Skin irritation due to scratching that causes inflammation
- Intake or use of steroids, and certain medications that contain halogens, lithium, barbiturates or androgens, and exposure to certain chemicals.

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