Acne is a disorder that causes outbreaks of skin lesions commonly called pimples. It is caused by the skin's oil glands making too much sebum, an oily substance, which leads to plugged pores. It also can be caused by the rapid production of a bacteria P. acnes. Acne lesions occur mostly on the face, neck, back, chest, and shoulders. It is the most common skin disease. Although acne is not a serious health threat, severe acne can lead to disfiguring and permanent scarring.

Almost all teenagers get acne at one time or another. You haven't done anything to cause your acne. It's not your fault if you have it. Pimples are caused when oil ducts in the skin get plugged up and then burst, causing redness and swelling. Although there are many myths about acne, the following are the three main factors that cause it. When you begin puberty, certain hormones, called androgens, increase in both males and females.

All acne is a disorder of the pilosebaceous unit, which is made up of a hair follicle, sebaceous gland, and a hair. These units are found everywhere on the body except on the palms, soles, top of the feet, and the lower lip. The number of pilosebaceous units is greatest on the face, upper neck, and chest. Sebaceous glands produce a substance called sebum, which is responsible for keeping the skin and hair moisturized.

Your immune system plays a role too. Some people are extra sensitive to the bacteria that get trapped in their hair follicles.

Acne usually starts around the time you reach puberty, and usually will be mild. Often it will last for about 5 years, but can persist for as long as 10-20 years. About 25% of teens who have acne will still have it when they turn 25. The cause is not understood, but it's becoming more common for women who are in their 20s, 30s, and 40s to develop acne, often for the first time. Temporary acne is often seen on the faces of newborns.