Period Pain Is Not Just That One Day
The short answer
Two or three days a month, days you learn to leave open in advance — why do they hurt? What breaks down on that day is not made on that day. It is built up over the preceding twenty days, and however the body has been during that time rests on that day. If the pain grows heavier year after year, if it hurts on days that are not your period, or if painkillers stop working, a gynecological exam should come first.
Contents
When planning a trip or setting an exam date, certain days get avoided. Two or three days a month, set aside in advance.
What happens on those days can be said briefly. The uterus contracts, and so it hurts.
What breaks down on that day is not made on that day. It is built up over the preceding twenty-odd days.
Rebuilt Whole, Once a Month
Inside the uterus there is a single lining. Its surface layer thickens with each cycle, then sheds, then grows back from the layer left behind.
Not many tissues in the body do this. Skin sheds gradually; bone changes over a long time. This lining thickens over a few weeks and then sheds all at once.
What stands out more is what comes after. Anywhere else in the body, losing this much tissue at once would leave a mark where it healed. But this lining heals without scarring. And then it does the same thing again the following month.
As the Tissue Thickens, the Blood Vessels Grow With It
If only the tissue thickened, the story would be simple. But when tissue thickens, it needs more blood to match, and that means blood vessels have to grow into it as well.
So as this lining thickens, blood vessels grow inside it at the same time. They do not grow straight; they grow coiled, like a spring. That is where the name spiral artery comes from. Fitting a long vessel into a narrow space leaves no choice but to coil it.
A month later, when this lining sheds, the vessels that grew inside it are severed along with it. A large part of what happens on that day comes from here.
Breaking It Down Is an Inflammatory Response
When tissue breaks down and blood vessels are severed anywhere in the body, what follows is set. An inflammatory response. The vessel walls become easier to leak from, immune cells gather at the site, and the work of clearing away what has broken down begins.
The word inflammation sounds like a disease. Here it is different. The very thing the body does when you are injured, the lining of the uterus does on a scheduled sequence, every month. And it finishes without scarring.
Prostaglandins are also part of that sequence. They are widely known as substances that cause pain, but their job here is something else. They constrict the coiled vessels and contract the uterine muscle, sending out what has broken down. The pain comes along with that work.
The Preceding Weeks Hang Over That Day
The same thing happens every month, and yet how much it hurts differs from month to month.
That is because how much there is to break down on that day is decided beforehand. Depending on how thick the lining grew and how much the vessels grew inside it, the conditions on that day can also differ. What happens that day does not begin that day.
That does not mean a thicker lining always hurts more, however. How much a given day hurts is not decided in one place. The amount of substance released, how tightly the muscle contracts, the blood flow passing through, and the state of the nerves receiving that signal — these four decide it together. Setting up any one of them as the cause hides the rest.
The Same Days, Different Points of Intervention
What NSAIDs act on is this substance. They work by suppressing the side that produces it, reducing the amount made. The reasoning is clear, and it has long been established as a way to get through those days.
What herbal medicine aims at is different. Not the side that blocks the substance, but the inflammatory response set off as vessels are severed, the contraction response of the muscle, and the environment in which all of that takes place.
The two sides handle the same days but take on different parts of it. This is not a matter of choosing one or the other.
Looking only at the day that hurts, there seems to be nothing to work with but those days themselves.
If twenty days precede those days, the range you can look at widens accordingly. However the body has been during that time rests on that day. The idea that the cycle is a wave, not a number is the ground this stands on.
There are cases, though, that do not fit this sequence. If the pain grows heavier year after year, if the same place hurts even on days that are not your period, if the days do not change even with painkillers properly used — this is not something the preceding weeks will resolve. Something other than period pain may be present alongside it, and then a gynecological exam should come first.
I think this part is fortunate. What cannot be explained by looking at that one day alone becomes explainable when you look at the whole month.
Written by Dr. Heo Ji-young (PhD in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)
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