Here are four ways your underwear can affect your health.  

Tighty-whities turn 80 years old this week.  A company in Chicago started selling them on January 19th, 1935.  Before that, guys mostly wore boxer shorts, long underwear, or nothing.  Here are four ways your underwear can affect your HEALTH.

1.  Fertility.  You've probably heard that tighty-whities can affect a guy's sperm count.  And studies HAVE actually backed that up.  It has to do with temperature.

Ideally, a guy's junk should be two or three degrees cooler than his body temperature.  But tight underwear prevents that, because it keeps everything closer to the body.

2.  Silk underwear can give you jock itch.  Most of the time, jock itch is caused by a combination of eczema, a slight fungal infection, and sweat.  And silk isn't very absorbent, so people with jock itch are usually told to wear cotton underwear.

3.  Spanx can give you nerve pain.  They've been linked to something called "meralgia paresthetica".  (Pronounced mer-AL-gee-uh pair-es-THET-ica.)

Basically, they irritate the nerves in your abdomen and thighs, and cause tingling, numbness, or burning.  It usually goes away if you stop wearing them though.

4.  Black underwear can give you a rash.  A compound called PPD is used as black dye in a lot of CHEAP underwear.  And a lot of people are allergic to it.