Okay, I get that the lining of the uterus gets old, or stale, or whatever, and has to be changed every month. I think think it’s a terribly inefficiant and messy system, but I understand the logic behind it.
But why cramps? Is there any purpose behind the monthly agony, or is it just a sadistic joke from Mother Nature.
Also, what exactly is a “pill period”, how is it different from a regular period, and why do you get it?
It’s what you get for tricking us into eating that apple.
ETA: and to add something useful, a “pill period” is a period due to woman who are on the pill taking sugar pills for a week to induce a period, which being on the pill consistantly would prevent/reduce)
Doesn’t it have something to do with the contraction of muscles helping to push everything out?
Right, I get that. I want to know why bleeding occurs if it isn’t a “real” period.
I take The Pill for dysmenorrhia, and I was puzzling over some of the information on the packet.
Cramps are the uterus contracting to expel the unused lining.
A pill period is basically an anovulatory period, because when you’re on the pill you don’t ovulate. Ovulation and subsequent non-fertilization are what cause normal periods. If a woman that wasn’t on BC didn’t ovulate, she’ll usually have a late or missed period.
The cycle works like this:
Period starts on Cycle Day 1 and last for two to seven days. At this time the levels of progesterone in the body start dropping (making the temp’s go down if the woman is temping).
After the period (and sometimes during), the levels of Follicle Stimulating Hormone and estrogen start rising to mature the egg(s) and develop the follicle. This can last anywhere from a few days to months (if she has very irregular schedules). Average is 12 to 16 days (not the 14 that so many doctors love to quote).
All of a sudden there is a surge of Luteinizing Hormone (which produces those nice bright lines on an OPK) and the egg(s) pop out of the follicle and make their way down the fallopian tube. This occurs within about 12 to 36 hours of the LH surge.
The body then starts to increase the production of progesterone, in case the egg gets fertilized and implants (resulting in an increase in temperatures, which is clearly visible if you are temping). If it does implant, progesterone stays high for the rest of the pregnancy. If it doesn’t implant, after about 10 to 16 days, the progesterone starts dropping (along with temps) and it’s time for a period.
And the cycle starts all over again.
(Every woman is different though, and medical problems can make for a screwy cycle, this is just a typical cycle).
Basically, it simulates a regular cycle using synthetic hormones but doesn’t allow ovulation. The sugar pills simulate the drop off in progesterone, causing a period.
Think of it as an evolutionary pressure to be pregnant
To me, a “Pill period” was something like three days of light bleeding and no cramps or pain at all. And it came on exactly the same day of every month, regular as clockwork.
A biological feature doesn’t have to have a purpose. As long as it doesn’t disadvantage you in reproducing or kill you off before you reproduce, there’s no real reason for evolution to select against it.
I can’t come up with even a speculative “Just So Story” for why the pain of menstrual cramps might provide any evolutionary advantage, but maybe other posters are more creative.
What? My “Just So Story” isn’t creative enough for you?
See post Nos. 3 and 5.
No advantage, but not a disadvantage, either. Also, keep in mind that without reliable contraception an awful lot of us would actually have very few periods, what with being pregnant and/or nursing so much of the time.
On a related note, why are female humans always receptive to sex (well, not always… 
), even though they aren’t always fertile? Other mammals are only interested when they’re in heat, so what’s so evolutionarily special about women?
The thought is, that it is a great evolutionary advantage to have guys hang around you all the time. Protection within a group and all that
Yes, that’s exactly it. Women benefit from constant male attention because nobody knows when they’re fertile. That’s added to the benefit that (until modern technology), a woman could have a choice of provider from among multiple sexual partners regardless of the genetic father.
The sugar pills are inert, they are just included in the pack as a reminder. I always threw them away…I was actually somewhat insulted that the drugcos thought I was too ditzy to start the pills again on the right day if I stopped taking them for a week.
It is the stopping of the active pills that triggers the period…you can stop a few days early or take a few extra ones to speed up or delay the onset of your period. Mine always started 2 days after the last active pill and I believe that is typcial
Seconded.
Because of the muscle contractions, bleeding and so on, it’s basically downtime anyway (that is, it wouldn’t be a good time to go hunting or anything). So there’s not a huge selective pressure on removing that pain.
Just as there’s little selective pressure on childbirth not being so painful.
Kind of the opposite - better-developed babies have a survival advantage over premature ones, which selects for birth size of “just barely able to squeeze out”.
Correct. The last week or so of pills you take have progesterone in them. When you stop taking the progesterone (either by taking the sugar pills or just stopping all together), you menstrate.
and you can medically supress your periods without ill effect. I have one a year, just before the annual spelunking of the coochie and mammosqueeze. And as soon as the plumbing gets surgically yoinked out, it will stop permanently.