I cannot describe the excitement that comes over me when I feel the first tingles of menstrual cramps. While most woman find this one of the worst symptoms of PMS/PMDD, it is my absolute favourite. Generally what it means is that in around 12 hours I will get my period. And in my head I hear the beginnings of this song…

Today I bled. And on discovering this my brain put Händel on full volume and I thanked all the Gods and Goddesses that this day had finally come. I had been released from my shackles and could enjoy the world once more.

Two weeks of sanity! Oh the things I could do! Suddenly I am funny again. I can make jokes that are clever rather than nasty. Suddenly my brain is not foggy and heavy, but instead sunbeams escape from my brain out through my eyes. Suddenly my body feels light and lithe rather than like a boulder that I must drag along. And although my cramps are at this point agonising, I dare not take paracetamol or ibuprofen to ease my suffering for this is the most satisfying pain of all.

And it is in this glorious mood at the beginning of another cycle that I am going to write about the menstrual cycle. Only in this state of mind can I write lovingly about such an atrocious bodily function.

For anyone who has any trouble with their period, monitoring your cycle is of the utmost importance. Whether you are irregular, or like me suffer from severe symptoms, monitoring your cycle helps you identify trends and/or anomalies (I use this app to help me https://play.google.com/store/apps/details?id=com.period.tracker.lite&hl=en). It wasn’t till I started to look at my PMDD scientifically that I begun to understand the process that causes my symptoms. I was amazed at how little I knew about the menstrual cycle, especially considering how much it affected my existence. So here I provide a summary for you, hopefully explained simply and effectively for your benefit.

The first mistake I used to make was that I thought that day 1 of my cycle was the first day after the bleeding stopped. WRONG! So wrong (seriously, how could I think that for so long???). Day 1 is the first day that you bleed. For me that is today (praise be!). For the next 5 or so days my uterine layer is shed resulting in what is known as “menstruation”. After this my uterine layer begins to thicken again, preparing for the potential of a fertilised ovule. At around day 11 ovulation begins (However, doesn’t occur generally till day 14). An egg is released from one of my ovaries, she makes her way down my fallopian tube hoping to get a chance date with the Usain Bolt of sperms. As she lingers there, waiting for her prince to come, my uterine layer continues to thicken, making a nice bloody bed for the potential baby zygote to rest on. My uterus is not as patient as my ovum and if she if isn’t fertilised my uterus eventually says “enough is enough” and the ovums last hopes are dashed as she is flushed out by the onset of menstruation once again. This process occurs generally over 28 days. The important days to remember are #1 – the day you bleed, and #14 – the day ovulation generally occurs.

This doesn’t seem to be that bad. How can such a simple process turn some woman into such nutters? Well the description above is a very brief description of what happens with your “bits” in a physical sense. What causes PMS and PMDD is more of a chemical process. I’m talking about hormones – of which I have a volatile love-hate relationship.

Day 1: When you start bleeding and shedding your uterine layer, your ovaries are already selecting and preparing your next egg for release. This process is triggered by the release of Follicle-Stimulating hormone (FSH) – released from the pituitary gland (a scrotum looking gland in your brain). At this point in your cycle Estradiol and Progesterone (the two hormones involved in PMDD and the focus of this explanation) are both at low levels.

Days 2 – 13: As the chosen follicle (an egg and its surrounding sack of fluid) is developed it begins to secrete estradiol which triggers the regeneration of the endometrium (uterine lining) after menstruation.

Day 14: The egg is now fully developed and a huge surge of Lutenising hormone (LH) is released from the pituitary gland to signal it to be released from the ovary – also known as ovulation. The egg bursts out of its follicle and begins its (often unsuccessful) journey down the fallopian tube. The rest of the follicle turns into this sort of squiggly donut called the corpus luteum.

Day 15 – 25: As the egg starts to wonder if she will ever find “the one”, the corpus luteum gets to work. It releases a hormone called progesterone (its my fave) which tells the uterine layer to start getting all bloody and nutritious making it ready for a baby.

Day 26: Eventually, if the egg doesn’t get its long awaited date with her sperm, the corpus luteum starts to wither and disappear. This means the end of progesterone release and also a drop in estradiol.

Day 28/1: When the levels of estradiol and progesterone fall to a certain level this triggers the shedding of the uterine layer which leads to the cycle beginning all over again.

So… Estradiol and Progesterone are the important ones for PMDD. Earlier I said progesterone was my fave hormone (I fangirl over this one). A paper called Estrogen and Progesterone in Plasma in Relation to Premenstrual Tension from the Journal of Steroid Biochemistry gives a good description in its summary of the interplay between these two hormones.

“Plasma concentration of estrogen and progesterone were measured during the last 6 days of the menstrual cycle in women with premenstrual tension, and compared with a group of healthy women. Those women with anxiety as the main symptom had significantly higher estrogen levels on days 5-2 before the onset of menstruation. On days 6-4 they had lower levels of progesterone. Estrogen – progesterone ratios were significantly higher on days 6-3 before menstruation.”

Scientists aren’t exactly known for making things easy to understand in their scientific papers. So I’m going to try and explain this to you in spoken English.

This one time when my PMDD got really quite bad my Mum (Hi Muttie!) booked me in to see this great doctor called Tessa Jones. When I went to see Tessa she made me do all of these weird tests. First, she made me collect a single urine sample, then she made me collect all my urine from an entire day (sooooo much admin), she made me get a blood test, and the last and most bizarre thing she made me do were some squats in her office to check my flexibility. Turns out that flexibility is associated with high levels of estrogen – which is why boys are generally a bit shit at it. And as I am quite flexi it turns out that this was an indicator of PMDD. Tessa explained that PMDD is caused by estrogen dominance. My ratio of Estrogen and Progesterone was all out of whack. Either my corpus luteum wasn’t producing enough progesterone, or my body was producing too much estrogen post ovulation and it caused me to be anxious and generally a bit (sorry, quite) nuts. So as the paper above described, post ovulation I present high levels of estrogen and low levels of progesterone. Progesterone is a great hormone. It makes you all calm and relaxed and sleepy (not that I need any help with the sleepy part!). When you are low in progesterone or it is masked by high levels of estrogen you don’t get that nice relaxed feeling, instead insanity.

So as you recall from the explanation on the menstrual cycle on day 1 both estrogen and progesterone levels are low. Menstruation marks the end of estrogen dominance that my body experiences post ovulation. That is why I love getting my period. I am more than happy to have blood pouring out of my foux-foux and feeling like my uterus is being squished in a vice just to experience the effects of low levels of hormones. And this is why blessed is the day I bleed! Hallelujah!

Sorry for the abrupt ending but life as a sane person is too fleeting to be spent creating a well crafted and satisfying one.

Oh, I almost forgot. In case my description of the menstrual cycle was a bit vague/confusing here is a kitsch-ish scientific animation for you…