There's something else too - PMT is real. It makes us crabby, humourless and short-tempered, such that our nearest, dearest and, actually, anyone else even relatively close had better watch out.
What it doesn't do is make us insane, irrational or somehow lacking a sandwich in our lunchbox.
Oh yes. The monotonous beeping noise from the metal detector toy the toddler isn't playing with but won't allow to be turned off is irritating. Picking up towels and turning off lights after people is annoying. Being yelled at from another room does my head in. Being asked five times to do the same thing that I'm already doing drives me nuts (only metaphorically) and being expected to magically divine the location of things is a little trying. But none of that will vanish next week.
It's just that today my normally, ahem, boundless patience is a little depleted. So the rage is nearby, probably lurking under another dropped toy.

Mother Nature must have had a reason for doing this to us. She usually does. Can't imagine what though unless it's her way of preparing us for the menopause. You see, PMT gets worse as you get older so by the time a hot flush hits, you may well be very glad to see the back of menses and all that goes with it.
Or it could be her way of saying you need to get out more. In younger, less predictable days, life was so all over the place and up and down, there was nothing much fixed to measure mood against. These days it's the same old dirty clothes, overflowing in box and emergency in Pontypandy.
Whatever. The thing is just because PMT makes reactions a little, perhaps, more intense than they were last week and will be next week, we are actually still the same people. So any man who even thinks "oh hell, she's batshit bonkers this week cos the painters are due in" - and we know you do - best think again. We are simply the same woman, only slightly enthusiastic about some things - like yelling.
Don't say: "Oooh, are you due on? I'd best keep out the way."
Do say (probably from a safe distance): "What can I do help you and make you feel better?"