The key to getting rid of underarm odor starts with personal hygiene. As a general rule, men suffer from underarm odor more than women. Since most women shave their armpits, they get rid of more of the bacteria that cause underarm odor [source: WebMD]. If you're not shaving your armpits, washing this area regularly will cut down on odor-causing bacteria.
Showering once a day may not be enough. You may need to shower in the morning and the evening and use an antibacterial soap or body wash. When you're done washing, towel off thoroughly, then apply an antiperspirant. Remember, we're going for two things here: getting rid of bacteria and keeping your underarms dry.
Personal hygiene doesn't just stop at washing your body. If you're prone to sweating, chances are your clothes soak it up. That makes your clothes a breeding ground for bacteria. Wash your clothes frequently and don't wear something more than once between wash cycles. If you exercise, wash your workout clothes as soon as possible. Your clothes may dry after soaking up all that sweat and not seem to smell that bad, but the bacteria are still there. Keep your sheets clean, too. Wash them regularly and don't hop in the sack after a sweaty day and no shower.
Diet is something else to consider when fighting underarm odor. Believe it or not, fatty foods and foods heavy in garlic, curry and onions can contribute to body and underarm odor. These foods can seep through your pores and add to the bad smell the bacteria produce. Research has also led some to believe red meat can add to offensive underarm odor. Finally, foods like red peppers that make you sweat don't help in your goal of staying dry [source: WebMD].
While prevention is essential, some with chronic underarm odor need more help. We'll get into that in the next section.