The reason it did take me so long to work it out was that I didn't realise what premenstrual syndrome's actually like. Ever since I was a kid I've known I've got moody in the day or two before my periods, but that's normal. Lately, I'd noticed that I was getting in a terrible emotional state about 8 or 9 days before my period - but I hadn't linked that to PMS because it seemed far too early in the month. It's only been since I looked things up last night that I've known that actually, 8 or 9 days before is classic PMS.
Apparently, there are three levels of severity of PMS. About 80% of women experience tearfulness, irritability and/or bloating before their periods. About 20-40% of women experience premenstrual distress, generally called PMS or PMT, where the change in behaviour is bad enough that other people notice it. And about 3-8% of women get the full-blown form of premenstrual syndrome, sometimes known as premenstrual dysphoric disorder (PMDD). It seems pretty damn certain this is what I have.
Now, I thought that PMS was related to having dodgy hormone levels. Apparently, this isn't the case. The vast majority of women with PMS have perfectly normal hormone cycles - and here's a link to a handy graph to show what goes on. You see that bit about day 23 or so when progesterone levels start to max out? That's the time when I go utterly bugfuck, to borrow a phrase. Depressed and irritable, and in serious danger of actually hurting myself.
Having managed to self-diagnose once again, I started looking into the treatments. At that point, my head exploded. It would appear that the most common treatments for PMS involve putting extra progesterone into the body, either through the Pill or hormone patches or suppositories inserted in places I'd really rather not. Um... but isn't it the time when I have the most progesterone in my body that I'm most bugfucked? Yes? So how the hell would putting more in help?
The PMS Disease Profile notes sagely that There is some debate as to whether progesterone causes or relieves PMS symptoms, but the consensus seems to be that progesterone and synthetic progestins can cause PMS types of mood symptoms. Since progesterone and progestins can also relieve symptoms it seems best not to prejudge its role in the cause of PMS. It is interesting that anti progesterone drugs (RU-486) do not make the symptoms go away. But it's all right for them to write all that - it's me that'll be fucked if I go on the Pill and it makes me even more psycho than my body does by itself! Argh! I need a medical professional with a big brain and a big library to sort me out now, and I'm not going to get to speak to one until Monday!