The Guy's Guide to PMS
"If guys got PMS, there would be a national holiday once a month so they could take off and rest," says Moore. "They should feel fortunate that they don't have to go through it, but they should also acknowledge that (a) women don't choose to have PMS, and (b) they need to be supportive of their friends or partners who do have it," she adds.

What's a sensitive guy to do? Start by trying to understand what's going on. "Most guys don't know what parts of a woman's body exist, much less how they might work together to cause PMS," says Bruce Bekkar, M.D., an obstetrician-gynecologist and clinical instructor of reproductive medicine at the University of California in San Diego and co-author of Your Guy's Guide to Gynecology (North Star Publications, 2000). If that's the case with you, here's a cheat sheet:

• Be supportive. Listen to what the woman in your life has to say, and face the fact that PMS is real. It's a physical and emotional condition, not a made-up excuse she uses just to bully you around. But take caution: the best time to discuss PMS isn't while she has it.
  
• Don't add extra stress to her life. If the two of you are due to have a highly sensitive conversation ("I am so going to that bachelor party!"), be smart and save it for later.
  
• Avoid temptation. Don't tempt her with foods or activities that will only make her symptoms worse, such as chocolate or sitting down for a Star Trek marathon. Instead, offer to share a salad, or take a walk with her.
  
• Most importantly, don't take her reactions or responses personally.

And ladies, talk to your guy, as well. Let him know that you realize you can get bitchy, and that you don't mean it. If he still insists on throwing out comments like "Oh, here it is again," you might want to run Moore's favorite piece of advice by him: "Men need to know that jokes about PMS can be hazardous to their health."