Puberty doesn't happen all at once — it happens in stages.
For example, a girl's breasts may start to grow, but she may not get her period until years later.
Some teens find that they're turned on (horny) a lot.
As you get older, these feelings probably won't be as strong.
Some guys develop swelling underneath their nipples when they're going through puberty, which can look like the start of breasts, but it's probably temporary.
It happens to two out of three guys, and it can last for a few years. If you have problems controlling your pimples, call a nurse or doctor for help.
During puberty, you'll also start getting your period.
This could lead to a difficult time in the controlling erections department.
Often, the erection happens at inappropriate times -- on the way home from school, at the swimming pool, or at the breakfast table. Erections occur when the "erection chambers" in the penis, called the corpora cavernosa, fill with blood. Your brain sends signals to nerves in the penis via the nervous system.
How long this "growth spurt" lasts and how tall you will be at the end of it depends on a lot of things — but mostly it has to do with how tall the other people in your family are.
During puberty, your breasts will change size and shape. You may not even notice this because it's a very subtle and slow change. The inner lips of your vulva will become more prominent and may stick out from the outer lips. Vulvas are as different and diverse as faces, and that's normal.