The fabulousness that is rubberneck came up with this fine description of the low-level seethe that is PMS:
I may also be a bit PMSy, but since my working theory is that monthly irritability could have had evolutionary benefit by causing a woman to re-assess her current situation through worst-case-scenario lenses, as an aid to prudent decision-making over the course of time, playing the PMS card isn't so much as excuse for my being pissy as it is a warning that the pissiness will be allowed to pass over and through me, so that only I will remain. Or something.
As for myself, PMS isn't so bad, but when I'm in The Red Tent, I feel like screaming "Midol! Fuck that shit! Pabst. Blue. Ribbon!" [/Dennis Hopper "Blue Velvet"]