Gynaecology · Women's Health
Adenomyosis vs endometriosis: what's the difference?
They sound alike, they're often confused and they frequently occur together — but they aren't the same condition. Here's a clear, evidence-based guide to how they differ and why telling them apart matters.
If you've spent years being told your period pain is "just part of being a woman," you're not alone — and you're not imagining it. Two of the most common causes of severe period pain, heavy bleeding and pelvic pain are endometriosis and adenomyosis. Because they share so many symptoms, they're easily mistaken for one another. Yet where the problem actually sits — and how it's best managed — can be quite different.
The one difference that matters: location
The simplest way to separate the two comes down to where the tissue grows.
Endometriosis
- Where it grows
- Outside the uterus
- Common sites
- Pelvis, ovaries, bowel and bladder
- Hallmark symptoms
- Period pain, pelvic pain, pain with sex and sometimes difficulty conceiving
Adenomyosis
- Where it grows
- Inside the muscular wall of the uterus
- Common site
- The body of the uterus (the myometrium)
- Hallmark symptoms
- Heavy periods, intense cramping and a persistent "dragging" pelvic ache
In short: endometriosis is largely a condition of the pelvis, while adenomyosis is centred on the uterus itself.
What they have in common
Despite the different address, these two conditions are closely related. Both are driven by oestrogen, share very similar tissue characteristics and appear to develop through overlapping biological pathways — so much so that researchers increasingly debate whether they may be two expressions of the same underlying disease. Together, deep endometriosis and adenomyosis are estimated to affect around 200 million women worldwide.
Both also tend to cause the same headline symptoms: painful periods, heavy menstrual bleeding and pelvic pain. That overlap is exactly why they're so easily confused — and why a careful assessment is worth the effort.
Endometriosis, in more detail
Endometriosis affects up to about 1 in 7 women of reproductive age. Its impact reaches well beyond an uncomfortable period:
- Around 90% of women with endometriosis experience pelvic pain — including period pain, pain outside of menstruation and pain during sex.
- About 1 in 4 report difficulty falling pregnant.
Because the tissue can settle in different places and to different degrees, symptoms vary widely. Some women have severe pain with only minimal disease; others have extensive disease with surprisingly few symptoms. You can read more about the full range of endometriosis symptoms and how the condition is assessed.
Adenomyosis, in more detail
Adenomyosis is defined by lining-like tissue being found within the muscle of the uterus. As it takes hold, the uterus can become bulky and tender. The classic picture is heavy periods, intense cramping and a dragging pelvic ache — although, importantly, some women have no symptoms at all.
For a long time, adenomyosis was considered a diagnosis that could only be confirmed after a hysterectomy. That meant it was under-recognised, particularly in younger women — something that has changed considerably in recent years.
They often travel together
One of the most important things to understand is that endometriosis and adenomyosis frequently coexist — and both can occur alongside fibroids. Having one raises the likelihood of finding the other. This matters because treating a single condition while missing a second can leave symptoms only partly explained or only partly improved.
How they're diagnosed today
Encouragingly, neither condition necessarily requires surgery to be suspected:
- A skilled transvaginal ultrasound — and in some cases MRI — can now identify features of both endometriosis and adenomyosis without an operation.
- For endometriosis, surgery (laparoscopy) has traditionally been the definitive way to confirm the diagnosis but increasingly a working diagnosis is made from symptoms combined with imaging.
Why getting the label right matters
Where the tissue sits influences the options worth discussing, how your fertility is considered and how a future pregnancy might be planned and monitored.
The evidence here is nuanced. Both conditions are associated with reduced fertility, with the effect appearing larger for adenomyosis. In pregnancy, adenomyosis has been linked with higher rates of certain complications — including miscarriage, pre-eclampsia and preterm birth — while more severe endometriosis has been associated with a low-lying placenta (placenta praevia). Intriguingly, some pregnancy risks once attributed to endometriosis may in fact be driven by coexisting adenomyosis.
This is general information, not a prediction about any individual: many women with either condition go on to have healthy pregnancies. But it's a clear example of why pinning down the right diagnosis is so worthwhile.
A word on being believed
If it has taken a long time to get answers, that experience is common — not a personal failing. On average, endometriosis is diagnosed 5 to 12 years after symptoms begin and most women see three or more clinicians before receiving a diagnosis. Persistent period pain and heavy bleeding are common but they are not something you simply have to live with.
Treatment: what to expect
Management is tailored to your symptoms, your goals — including whether you're hoping to conceive — and which condition or combination, is present. For women with symptoms who aren't currently trying to fall pregnant, hormonal medications such as the combined pill or progestogen-only options are usually the first step, with surgery considered when medical treatment isn't effective or suitable. You can read more about endometriosis treatment options here.
It's worth being realistic. Hormonal treatment helps many women but not everyone and symptoms can return after stopping. The right plan is the one built around your individual situation — which is where specialist assessment comes in.
When to see someone
It's worth speaking with your GP about a referral to a gynaecologist if you have:
- period pain that interferes with work, study or daily life
- consistently heavy periods
- pelvic pain between periods or pain during sex
- difficulty falling pregnant alongside any of the above
Frequently asked questions
Is adenomyosis a type of endometriosis?
No. They're closely related and share similar tissue and hormonal drivers but they're considered distinct conditions. The key difference is location: endometriosis grows outside the uterus, while adenomyosis grows within the uterine muscle wall. They can occur separately or together.
Can you have both endometriosis and adenomyosis at the same time?
Yes — the two frequently coexist and either can also occur alongside fibroids. Because they cause overlapping symptoms, one can be present without the other being obvious, which is why a thorough assessment matters.
Which is worse, adenomyosis or endometriosis?
Neither is straightforwardly "worse." Both are benign (non-cancerous) but can significantly affect quality of life, periods and fertility, and their impact varies from person to person. The more useful question is usually which condition — or combination — is present and how it's affecting you.
How do I know which one I have?
A specialist assessment, usually including a transvaginal ultrasound and sometimes MRI, can identify features of both. Importantly, a normal scan doesn't rule either out. If symptoms persist despite clear imaging, it's worth continuing to seek answers.
Can endometriosis or adenomyosis be cured?
There's no simple cure for either, but symptoms can often be managed well with the right plan — tailored to your symptoms and whether you're hoping to conceive. Even surgery isn't always the end of the story, as symptoms can sometimes return.
Where can I see a gynaecologist for endometriosis on Sydney's North Shore?
Dr David Krones consults at North Shore Private Hospital, Level 3, Suite 3A/3 Westbourne St, St Leonards, with operating privileges at North Shore Private and The Mater Hospital. The rooms are convenient to surrounding North Shore suburbs including Crows Nest, Chatswood, Lane Cove and North Sydney. Ask your GP for a referral, or phone 02 9053 1245.
More questions? See our gynaecology FAQ.
Seeing a gynaecologist on Sydney's North Shore
Dr David Krones consults from Level 3, Suite 3A at North Shore Private Hospital in St Leonards, and operates at North Shore Private and The Mater Hospital in Crows Nest — within easy reach of Crows Nest, Chatswood, Lane Cove, Willoughby, North Sydney and the wider North Shore. If persistent period pain, heavy bleeding or pelvic pain is affecting your life, a referral from your GP is the first step to a specialist assessment.
Concerned about period pain or heavy bleeding?
Dr David Krones is a specialist obstetrician and gynaecologist consulting on Sydney's North Shore, with a subspecialty interest in endometriosis, pelvic pain and advanced laparoscopic surgery. If any of the above sounds familiar, speak with your GP about a referral for assessment.
Phone 02 9053 1245 · Request an appointment · admin@drdavidkrones.com.au
This article is general educational information and is not a substitute for personalised medical advice. It does not establish a doctor–patient relationship. Please consult your GP or specialist about your individual circumstances.
References
- As-Sanie S, Mackenzie SC, Morrison L, et al. Endometriosis: A Review. JAMA. 2025;334(1):64–78. https://doi.org/10.1001/jama.2025.2975
- Chapron C, Vannuccini S, Santulli P, et al. Diagnosing adenomyosis: an integrated clinical and imaging approach. Hum Reprod Update. 2020;26(3):392–411. https://doi.org/10.1093/humupd/dmz049
- Donnez J, Stratopoulou CA, Dolmans MM. Endometriosis and adenomyosis: similarities and differences. Best Pract Res Clin Obstet Gynaecol. 2023;92:102432. https://doi.org/10.1016/j.bpobgyn.2023.102432
- Vercellini P, Viganò P, Bandini V, et al. Association of endometriosis and adenomyosis with pregnancy and infertility. Fertil Steril. 2023;119(5):727–740. https://doi.org/10.1016/j.fertnstert.2023.03.018