1. Puberty lasts for several years. It is the stage of your life when your body is changing from the body of a child to the body of an adult. Hormones, which are natural chemicals in your body, are orchestrating these alterations in your body.

2. During puberty, one breast might grow larger than the other. Once your breasts start growing, the differences will most likely be slight. And your breasts will even out before they are finished developing. But if they don't, no need to worry since many women's breasts don't match each other exactly.

3. It might take a while, perhaps even a year, for your periods to become regular every month. During the first year, your cycle (from the start of one period to the start of the next) may be as short as three weeks or as long as six weeks. Even after your periods become regular, exercise, stress or a change in diet could throw it of track. If you are sexually active and skip a period, talk to your health care provider immediately — you could be pregnant.

4. Nearly three million cases of sexually transmitted diseases (STDs) occur among teenagers every year.

5. Suicide is the fourth leading cause of death for persons between 10 and 14 years of age and the third leading cause of death for those 15 to 24 years old. Actions or talk of suicide is a cry for help in itself. Most teenagers are looking for acceptance, understanding, attention and love.

6. Teenagers are increasingly expressing dissatisfaction with their bodies, although more often than not they are properly proportioned. Much of the blame is being directed at media for portraying idealized body images that are unrealistic for most people. This idealized body image among young women — and increasingly for young men, as well — is leading to an increase in the number of teenagers with eating disorders. However, eating disorders are not just a preoccupation with food, dieting and weight. They are serious mental disorders that can have serious consequences. Two disorders are bulimia and anorexia nervosa.

7. The average age for a girl to try alcohol is 13-years-old. It is the drug most often used by 12- to 17-year-olds. Although most parents think peer pressure is the main reason teenagers drink, 79 percent of teens say they drink to get drunk or because it "feels good."

8. A recently published report found a sharp rise (from 5.3 percent in 1993 to 11.9 percent in 2001) in frequent binge drinking was noted among women attending all-women's colleges, and a lesser, but still significant, increase of the same behavior for women in coeducational schools.