The biological trip to manhood is all about testosterone, also known as the "male" hormone (even though women have some of it, too). For boys, the journey to maturity may take as long as 8 years, but the signs of masculinity begin sprouting as soon as testosterone starts to flow. Usually between the ages of 10 and 14, the brain sends a message to the testicles to wake up and start pumping out testosterone, which triggers a multitude of changes, from a deepening voice and increasing body hair to a full-fledged sex drive and bigger muscles.
Here are answers to the six most common questions boys have about their developing bodies -- some of which they may be too shy to ask. They're all from YOU: The Owner's Manual for Teens, the latest book from RealAge experts Mehmet Oz, MD, and Michael Roizen, MD.
Is it okay to have wet dreams?
Absolutely. It means the plumbing in your sexual system -- primarily your circulatory system, which controls the blood flow that makes an erection -- is working just fine. Most guys start having wet dreams (ejaculating while asleep) somewhere between ages 10 and 14. Wet dreams remind us of how closely the mind and body are related. Most guys who have wet dreams (not all do) outgrow them within a few years, once their hormone levels settle down.
I've heard erections can happen for no reason, even when I'm sleeping. Is that true?
Yep. They're called spontaneous erections. They're nothing to be concerned about (unless they happen precisely when the teacher calls you to the front of the room). The good news: Spontaneous erections are a sign of good health. You may get them every few hours at night because that's when there is greater blood flow to the area.
What's up with masturbating?
Both boys and girls may feel the need for the release of an orgasm occasionally or regularly, and masturbation is a healthy and normal way to experience sexual pleasure without the risks associated with intercourse. Usually, people masturbate in bed or in the shower. None of the myths about overdoing masturbation -- like hairy palms or going blind -- are true. But you're overdoing it if you're masturbating in public or have rubbed yourself raw.
Mutual masturbation means touching another's genitals and being touched, to give and receive pleasure. But be aware that human papillomavirus (HPV) can be found under fingernails. This virus can cause genital warts; in women, it also increases the risk of cervical cancer. If you pick up HPV on your fingertip from your own or someone else's genitals and then touch your own or someone else's, you can transmit the virus. This is an excellent reason to get immunized against HPV, whether you are male or female.
When can I get a girl pregnant?
As soon as you can ejaculate, you're making sperm that can fertilize an egg. In other words, even in early puberty, all guys are carrying a loaded gun that can shoot sperm. That's why unprotected sex, even at quite a young age, can result in pregnancy.
What's the best thing to do if I get hit in the groin?
Apply ice immediately to minimize swelling and make it feel better. But if the pain doesn't subside or it becomes worse after a few hours or if one of your testicles swells to the size of a grapefruit, see your doctor immediately.
How do I know if I'm getting "man boobs"?
Normal, healthy boys between the ages of 13 and 15 often get a little fatty tissue right behind their nipples that looks like breast tissue. If you are worried about it, try push-ups, pull-ups, and weight training to firm up your pectoralis (chest wall) muscles.
Usually, gynecomastia (enlarged breasts in men) goes away on its own. But if you become one of the rare guys with a serious issue, see a plastic surgeon about correcting the problem.
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