Personal Hygiene Image Gallery
Personal Hygiene Image Gallery

It's instinctual to raise your arms in excitement on a roller coaster, but this ride's home base, Thorpe Park in Surrey, England, has actually banned arm raising on hot days. See more pictures of personal hygiene.

Daniel Berehulak/Getty Images

Ugh. If the weather or the room is hot, or you've been exercising, or you feel nervous or excited, you might innocently raise your arm -- and be nearly knocked out by the odor emanating from your armpits. And if you're grossed out by your underarm stench, imagine how those poor people around you must be reacting. Underarm odor can be embarrassing. What's more, it can cause problems in social and professional relationships.

Some scientists believe that long ago, underarm odor helped attract humans to their mates [source: Feldman]. But it's obvious that for most of us, any such attraction has vanished from our culture. In fact, underarm odor is such a turn-off that a large amusement park in Surrey, England, recently banned customers from raising their arms when riding scary roller coasters during hot weather.

Today, there's a vast and sometimes confusing array of products and home remedies to fight underarm odor. For five ways that work -- and to sweeten the smell of your armpits -- read on.