If you’ve ever wondered what happens when you swallow chewing gum, why some navels are “innies” while others are “outies,” or whether you can catch a cold from wintry weather, wonder no more.

The paperback book “Why Do Men Have Nipples?” (Three Rivers Press, $12.95) contains the answers to these and about 160 other offbeat medical questions “You’d Only Ask a Doctor After Your Third Martini.”

Authors Mark Leyner and Billy Goldberg met when they worked together on the short-lived TV medical series “Wonderland,” which aired in 2000. Leyner was a scriptwriter and Goldberg, an emergency room physician, was his medical consultant.

In the book, Goldberg provides scientifically sound answers into which Leyner injects, if you will, humor.

When it comes to the human body, the authors know their onions – and know why peeling them brings tears to the eyes, which they explain.

There are nine chapters with topics that include eating, anatomical oddities, home remedies, drugs and alcohol, sex, the bathroom, aging, old wives’ tales, and medicine as portrayed on TV and in the movies.

For example: What would happen to a patient if a Junior Mint fell into him during surgery, as happened in a “Seinfeld” episode?

Viewers of “Seinfeld” will recognize other medical situations seen on the series: “bubble boy” disease, poppy seeds causing a “positive” result on a drug test, and a certain physical reaction that caused the insecure George Costanza considerable anguish after swimming in cold water.

The chapter on eating explains the cause of “ice cream headache,” and tells why spicy food makes the nose run and why there’s truth in the old joke about being hungry an hour after eating Chinese food.

When discussing home remedies, Leyner and Goldberg advise that putting butter on a burn, trying to remove earwax with a flame and drinking brandy to ward off frostbite are not good ideas. A good idea, however, would be to put that steak on the grill instead of on a black eye.

The authors set the record straight also about lip balm addiction, male menopause, the existence of a G-spot, eating after swimming, looking directly at an eclipse, and whether eating too much could make you explode (yes, they say, but it’s rare).

The topic of aging is saved, appropriately, for the final chapter, where we find out, among other things, why older folks turn gray, lose some ability to taste and develop age spots.

We also learn the truth about truth serum.

This entertaining and informative book has no index – providing one would have made it more useful as a reference work. There is no appendix, either, but since one of the authors is a physician, he might have removed it.