context: Have you ever finished a sweaty workout, and within minutes, noticed a peculiar smell? When " Jack" (not his real name) left the gym after basketball practice, he walked up to a group of friends. They immediately commented on someone's body odor, wondering which of them was the culprit. " When I realized it was me, I was humiliated," Jack said. " I quickly went to my locker and realized that I didn't have a deodorant at school. " I avoided all my friends that day. When I got home, I put my new deodorant in my backpack to make sure this never happens again." Jack is not the first (or last) teen to notice body odor. Bromhidrosis (another word for body odor) happens at puberty because of increasing hormones called androgens. These hormones are not active until puberty, which is why body odor wasn't a problem when you were a kid. While sweat itself is virtually odorless, bacteria use it as a breeding ground and multiply rapidly. What you smell is the products related to bacteria breakdown of keratin protein on the surface of your skin. Sounds disgusting, doesn't it? Chalk it up to an unpleasant fact of life! When you work out or move around in the heat or sun, your body produces sweat. Sweating is the body's way of regulating temperature. When sweat meets the bacteria on the surface of your skin, it produces an odor. That smell is what we call body odor (or B. O. for short). While body odor is usually associated with the armpits, bacteria can also produce odor in the groin, anus area, upper thighs, and feet, among other places. Thoroughly washing your skin with a wet washcloth and soap -- especially those areas prone to sweating -- can help prevent body odor. Remember that smelly feet can also cause smelly shoes. Treating your shoes with an over-the-counter deodorizer can help. Also, wear thick, absorbent socks if you can. If you want to be "odor-free" consider the following tips: Apply an antiperspirant at bedtime. This gives the product a chance to work while you sleep and are not sweating. If you apply antiperspirants after showering in the morning, the sweat you accumulate will wash away the product and render you defenseless against daytime sweating. Remember, deodorants do not prevent sweating. They mainly mask the smell of the sweat on your skin. Antiperspirants are chemical agents that reduce sweating. Many antiperspirant preparations also contain a deodorant, which helps to mask the smell. Check the product you use to make sure it contains an antiperspirant. Keep your underarms dry. Bacteria have a hard time breeding in dry areas of the body. Try a solution of hydrogen peroxide and water to fight body odor. Use 1 teaspoon of peroxide (3%) to 1 cup (8 ounces) of water. Wipe this on affected areas (underarm, feet, groin) with a washcloth. This may help destroy some of the bacteria that creates odor. If sweat from working out is your No. 1 cause of body odor, wash your workout clothes often. Sweaty gym clothes are a bacteria-breeding ground. Change your diet. Sometimes, fatty foods, oils, or strong-smelling foods such as garlic, curry, and onions, can seep through your pores and cause body odor (always see a doctor or dietician before making drastic dietary changes). If you have excessive sweating (called hyperhidrosis), talk to your doctor. There are a few treatment options for those with more severe sweating who desire more aggressive treatments. Also, certain medical problems can lead to excessive sweating. Your doctor can make a diagnosis and prescribe treatment. Shaving your underarm regularly will help prevent the accumulation of bacteria and can reduce sweat and odor. In some societies, body odor is accepted. But most countries today frown on body odor. In fact, some religions have strict guidelines about bathing practices and personal hygiene. The best way to fight body odor is through prevention. For most teens, proper hygiene -- like washing well and applying an underarm antiperspirant or deodorant -- should be enough.