Endometriosis Is Not "Just a Bad Period"
If you have endometriosis, there's a good chance someone has told you period pain is normal. Maybe a friend, maybe a parent, maybe a doctor. Maybe more than once.
You're not alone in that. Endometriosis affects around 1 in 10 women, which in the UK means more than 1.5 million people. That's roughly the same number of people living with diabetes. Yet the average wait for a diagnosis is almost nine years. Nearly half of women see their GP ten or more times before anyone gives their pain a name.
I see the impact of that wait in clinic all the time. By the time many women reach me, they've spent years wondering if they're overreacting. So let's start with the truth: you're not.
So what is endometriosis?
Endometriosis is characterised by tissue similar to the lining of the womb growing outside the womb. It forms small patches called lesions, most often on the lining of the pelvis, the ovaries and the surrounding organs. It has also been found much further afield, even in the lungs.
These lesions don't simply sit on the surface. They can grow into tissue, and they don't follow the rules of your menstrual cycle. They behave independently, which is part of why symptoms can feel so unpredictable.
It's also far more than a "period problem". Endometriosis is a chronic, inflammatory, whole-body condition.
The symptoms you can see, and the ones you can't
The best-known symptom is pain, especially during your period. But endometriosis can also bring:
heavy bleeding and anaemia
deep fatigue
low mood
in some women, pain so intense it causes vomiting
Part of that fatigue and low mood comes from the inflammatory messengers the body produces, which can slow thyroid function and affect how you feel emotionally.
Interestingly, some women have no pain at all.
Then there are the symptoms nobody sees. There's time off work, and worry about money. There are strained relationships and a changed sex life. Many women carry guilt, shame, anxiety and a sense of losing control over their own body. And then there's the well-meaning but unwanted advice. For many women, this invisible side is just as heavy as the physical one.
Not all endometriosis looks the same
There are three main types:
Superficial: the most common, making up around 80% of cases. These lesions are shallow, less than 5mm deep, and can look like tiny freckles on the lining of the pelvis. They're very easy to miss on a scan.
Ovarian cysts: often called "chocolate cysts", these are dark, blood-filled cysts on the ovaries.
Deep: this is where lesions grow more than 5mm into tissue or organs.
You may also hear endometriosis described in stages, from 1 to 4. I understand why "stage 4" is frightening, because we associate staging with cancer. But here's what surprises many women: the stage doesn't match how much pain you're in. Someone with a few small lesions can have severe pain, and someone with extensive disease may have very little. Updated NICE guidance in 2024 recommends that staging shouldn't be used to make treatment decisions.
Why diagnosis is so tricky
An internal ultrasound is usually the first step, and it's useful for deeper endometriosis. Neither ultrasound nor MRI reliably picks up the superficial type, though, so a clear scan doesn't rule endometriosis out.
The most definitive route is keyhole surgery (laparoscopy). During the procedure, a surgeon can look inside, take a sample, and remove lesions, cysts and scar tissue at the same time.
Surgery can bring great relief for some women, but it isn't a guaranteed fix. Removing lesions doesn't always remove the pain. Surgery also creates scar tissue of its own, so repeated operations deserve careful thought. The bigger picture matters: the whole body, not only what shows up in the pelvis.
Why does it happen?
The oldest theory is that some menstrual blood flows backwards through the fallopian tubes into the pelvis, carrying womb-lining cells with it (this is termed retrograde menstruation). The catch is that this happens in around 90% of women, yet only about 10% develop endometriosis.
A healthy immune system should spot these cells and clear them away. In women with endometriosis, that clean-up crew doesn't do its job. That's one reason we now understand endometriosis as an immune condition as much as a hormonal one.
In reality there's no single cause. It's likely a mix of:
genetics
hormones
inflammation
the immune system
the nervous system
new blood vessel growth feeding the lesions
gut and vaginal bacteria
environmental chemicals, such as dioxins and parabens
Each piece feeds the others, which is exactly why a single-lever approach so often falls short.
How I see it through a TCM lens
In Traditional Chinese Medicine, endometriosis is most often understood as Blood stasis. There's a classical saying that where there is no free flow, there is pain.
We also look at what sits underneath the stagnation:
Qi stagnation, often linked to stress
Cold in the lower abdomen
Depleted Kidney energy
Acupuncture and herbal medicine aim to restore flow and warmth to the pelvis. That sits very comfortably alongside what modern research tells us about inflammation and blood supply in these lesions.
Where to start
If you bleed heavily, ask for your iron to be checked. Heavy periods drain iron quietly, and low iron alone can leave you exhausted. From there, supporting endometriosis means looking at the whole system: hormones, inflammation, immunity, gut health and the nervous system together. I'll walk through each of those in the next two posts.
If you're living with endometriosis, or suspect you might be, I'd love to help you make sense of your symptoms. Book a consultation at Vale of Health or follow us on Instagram @valeof.health for more.