ADENOMYOSIS OR ENDOMETRIOSIS?
They are frequently confused, often coexist, and the difference changes what actually helps.
By Katie Rice | Accredited Naturopath & Nutritionist | Her Herbs Founder
If you have been told you have one of these conditions, there is a reasonable chance you have wondered whether it is actually the other. The symptoms overlap heavily. Both cause pelvic pain. Both cause debilitating periods. Both are frequently dismissed for years before anyone takes them seriously.
And in clinic, this is one of the most common sources of confusion I see. Women who have carried an endometriosis diagnosis for a decade, whose symptom picture has always looked more like adenomyosis. Women who have been told their pain is endo, had a laparoscopy that found very little, and been left without an explanation.
The two conditions are related but distinct, they are managed differently, and telling them apart changes what you should be asking for. Here is how to think about it.
The Basic Difference Is Location
Both conditions involve endometrial-like tissue growing where it should not be. The difference is where.
In endometriosis, that tissue grows outside the uterus. On the ovaries, the peritoneum, the pouch of Douglas, sometimes the bowel or bladder. It responds to your cycle, bleeds, and drives inflammation and adhesions in the places it has settled.
In adenomyosis, that tissue grows inside the muscular wall of the uterus itself. It bleeds within the muscle each cycle, which thickens the uterine wall, increases its blood supply, and makes it contract harder and more painfully.
That single difference in location explains almost everything about how the two conditions present differently.
How the Pain Differs
Endometriosis pain tends to be located wherever the deposits are. It is often one-sided or asymmetrical, can be felt deep in the pelvis, and frequently radiates to the lower back, hips or legs. Because deposits can sit near the bowel or bladder, the pain often has a distinctly non-uterine quality to it.
Adenomyosis pain is more central and more diffuse. Women describe it as heaviness, dragging, or pressure low in the abdomen, with cramping during the period that can be severe. It is the uterus itself hurting, and it often feels like it.
Neither pattern is diagnostic on its own. But if your pain is centred, heavy, and sits squarely behind your pubic bone, adenomyosis is worth putting on the table.
The Bleeding Is Often the Clearest Clue
This is the feature that separates them most usefully.
Heavy menstrual bleeding is a defining characteristic of adenomyosis. Flooding, clots, needing to change protection hourly, periods that leave you anaemic and exhausted. The thickened, more vascular uterine wall bleeds more, and it is the symptom that most often brings women to their doctor in the first place.
Endometriosis can involve heavy bleeding, but frequently does not. Many women with endometriosis have relatively ordinary flow and catastrophic pain. If your bleeding is genuinely heavy month after month, that shifts the picture toward adenomyosis, or toward both.
Pain With Sex, Bowels and Bladder
Cyclical bowel and bladder symptoms, pain with opening the bowels, and pain with sex that is felt deep rather than at the entrance are more characteristic of endometriosis, because deposits sit on or near those structures.
Adenomyosis can cause pain with sex too, usually through uterine tenderness and pelvic floor guarding rather than through deposits pressing on the bowel or bladder.
If your symptoms are strongly cyclical and clearly involve your bowel or bladder, that leans toward endometriosis.
What Examination and Imaging Show
On examination, an adenomyotic uterus is often enlarged and tender, sometimes described as boggy. In endometriosis the uterus may be a normal size, though it can be tethered or fixed by adhesions.
Imaging is where the two diverge most. Adenomyosis can often be seen on a good quality transvaginal ultrasound performed by someone specifically looking for it, and is seen clearly on MRI. Endometriosis is frequently invisible on imaging unless there is an endometrioma or deep infiltrating disease, which is why so many women are told their scans are normal while their symptoms continue.
This matters practically. A normal pelvic ultrasound does not rule out endometriosis. But a properly performed one can genuinely suggest adenomyosis, and it is a reasonable thing to ask for.
Why It Takes So Long to Separate Them
Both conditions are historically underdiagnosed, and for a long time adenomyosis could only be confirmed definitively by examining the uterus after a hysterectomy, which meant it was rarely diagnosed in women still in their reproductive years.
Imaging has improved considerably, and criteria for recognising adenomyosis on ultrasound and MRI now exist. But awareness has not caught up everywhere, and the older assumption that adenomyosis is a condition of women in their forties who have had children still shapes how it gets looked for. Younger women, and women who have not had children, are frequently overlooked.
If you have been investigated for endometriosis and nothing adequately explains your symptoms, asking whether adenomyosis has been considered is a legitimate question.
They Frequently Coexist
This is the part most women are never told. Adenomyosis and endometriosis often occur together, and having one does not exclude the other.
That has real consequences. A woman with both who has a laparoscopy for endometriosis may find her pain improves but never fully resolves, because the adenomyosis was never addressed. Being told the surgery worked while still living with heaviness and flooding is a genuinely disorienting experience, and it happens often.
If treatment for one condition has helped partially but not completely, the other is worth investigating.
Why the Distinction Actually Matters
It changes where the effort goes.
With endometriosis, the emphasis is often on inflammation, adhesions, deposit-driven pain in specific locations, and the bowel and bladder overlap. With adenomyosis, heavy bleeding and its downstream effects move to the centre of the picture. Iron depletion becomes a major driver of how you feel day to day, uterine cramping and prostaglandin activity dominate the pain, and supporting the uterine muscle itself matters more.
From a naturopathic perspective, the inflammatory and hormonal groundwork overlaps substantially between the two. But the priorities shift. In adenomyosis, ferritin and bleeding management move to the front. In endometriosis, gut health, adhesion-related pain and the bowel and bladder picture usually take more attention.
Treating both as though they are the same condition means part of what is driving your symptoms goes unaddressed.
What to Ask For
If you are trying to work out which you are dealing with, there are a few reasonable requests to make.
A transvaginal ultrasound with adenomyosis specifically in mind. Not every scan is performed with adenomyosis features in view, and asking for it to be considered can change what is reported.
Ferritin, not just haemoglobin. Iron stores deplete long before haemoglobin falls. If your periods are heavy, this is the single most useful blood test to have.
A clear account of your bleeding. Not "heavy", but how often you change protection, whether you pass clots, whether you flood, and how many days it lasts. That detail is what shifts clinical thinking.
Whether both are possible. Asking directly whether you might have both is a fair question and it prompts a different kind of assessment than asking about one.
Track Your Patterns
Separating these two conditions is largely a pattern recognition exercise, and patterns are almost impossible to hold in your head across months of symptoms.
Tracking pain location and character, bleeding volume, cycle timing, and bowel and bladder symptoms gives you something concrete to take to an appointment. A woman who can say her pain is central and heaviest on days one and two, that she floods for three days, and that her bowel symptoms are unrelated to her cycle is giving her doctor a very different picture from one who says her periods are bad.
That detail is often what moves an appointment forward.
If you want to go deeper on naturopathic support for adenomyosis, the Her Herbs Adenomyosis Series covers the full picture.
EXPLORE THE HER HERBS ADENOMYOSIS SERIES
A Note From Katie
"So many women come to me carrying a diagnosis that only ever explained half of what they were experiencing. They were told it was endometriosis, they had the surgery, and the heaviness and the flooding never went anywhere. Nobody had looked at the uterus itself. Knowing which condition you are dealing with, or whether you are dealing with both, is not a technicality. It decides where your energy goes, and you deserve to be putting it in the right place."
Katie Rice, Naturopath & Founder, Her Herbs
This content is for educational purposes only and does not constitute medical advice. Please consult your healthcare provider regarding your individual health concerns.
