In most cases, acne lasts for about 5 to 10 years, then goes away on its own. However, some adults in their 20s, 30s, and even 40s get acne. Acne occurs when pores in the skin become clogged with a mixture of oil and dead skin cells. Normally, this oil travels up through the pore and out onto the surface of your skin. However, if too much oil is produced, it can cause the cells in the pore lining to make a plug at the skin s surface.
Germs can grow below the plug, causing redness, swelling, and pimples.
Blackheads form when the plug goes through a chemical process they are not caused by dirt. Certain hormones produced by your body can make the skin glands more active, causing them to put out more oil. You are more likely to develop acne during the times when your body makes larger amounts of the hormones, such as during puberty. This is why so many teenagers get acne. The overall hormonal effect of the pill helps prevent acne from forming, which is why birth control pills often are used as a treatment for acne.