If you're a teen, chances are pretty good that you have some acne. Almost 8 in 10 teens have acne, along with many adults.

Acne is so common that it's considered a normal part of puberty. But knowing that doesn't always make it easier when you're looking at a big pimple on your face in the mirror

Acne is a condition of the skin that shows up as different types of bumps. These bumps can be blackheads, whiteheads, pimples, or cysts. Teens get acne because of the hormonal changes that come with puberty. If your parents had acne as teens, it's more likely that you will, too. The good news is that, for most people, acne goes away almost completely by the time they are out of their teens.

Who gets acne?

Both boys and girls get acne. But it may be worse in boys because they have more skin oils.

Heredity also plays a role. If your mother and father had bad acne, you may too.

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

For many people, acne fades by the age of 25, but it can continue well into the adult years.

What causes it?

There are four primary factors that influence your susceptibility to acne.

• Blocked hair follicles due to an overproduction of skin cells referred to as “keratinocytes.” These skin cells combine with a fatty material called sebum to form a plug in the follicle, resulting in acne.
• Enlarged sebaceous glands, responsible for producing sebum. Enlarged glands are common during adolescence. These glands are concentrated in areas such as the face, upper back and chest.
• Increase in bacterium growth. The increased sebum in the face, back and related areas promote the overgrowth of a type of bacteria referred to as “propionibacterium acnes” which results in acne.
• Inflammation due to bacteria growth. Sometimes an eruption occurs as skin cells and follicles become inflamed due to bacterial growth.
• Hormonal changes that typically occur during the teen years are often responsible for acne formation. Teens generally produce more sebum than adults, resulting in an increased incidence of acne. Other substances including oil-based cosmetics may contribute to a build up of fatty sebum in the skin, producing an environment that is more acne prone. Even excess humidity and moisture on the skin can contribute to acne.
• Some oral contraceptives (birth control pills) can make acne worse. Women should ask their physician to prescribe a pill that typically has a low activity of androgens

Things that often make acne worse

• Oil-based makeup, suntan oil and hair products
• Stress
• Hormonal changes, especially during menstruation
• Squeezing or picking at blemishes
• Hard scrubbing of the skin

Things that don't cause acne

• Dirt
• Chocolate or french fries
• Sexual activity
• Masturbation

How can acne be treated?

Many treatments are available for acne, including creams and medicines. Talk with your doctor about which options are right for you.

Does acne cause scars?

Acne, especially cystic acne, can cause scars in some people. You can help reduce scarring by not squeezing or picking at blemishes. Also, avoid scrubbing your skin. If you do get scars, treatments are available.