Endometriosis is slowly becoming more recognised, but adenomyosis is still relatively unknown. Many people have never heard of it until they’re given the diagnosis themselves, often after years of being told their symptoms are “normal”.
Adenomyosis is only just starting to gain wider recognition, largely because more women are questioning what they’ve been told about periods, learning what isn’t normal, and advocating for proper investigation and care. As conversations around menstrual health open up, conditions that were once overlooked are finally being named.
While endometriosis and adenomyosis are different conditions, they’re often confused, and frequently missed, because symptoms can overlap and awareness remains low. Understanding the difference matters, especially when symptoms persist despite treatment, or when fertility is part of the picture.
Both conditions involve tissue similar to the lining of the womb (the endometrium). The key difference is where that tissue grows.
Endometriosis happens when tissue similar to the endometrium grows outside the womb—including on the ovaries, fallopian tubes, bowel, bladder, or walls of the pelvis.
This tissue reacts to hormones, just like the womb lining does. But because it’s in the wrong place, it can cause inflammation, scarring, and pain.
Endometriosis affects around one in ten women, and it’s particularly common among those experiencing fertility problems.
Adenomyosis occurs when endometrial-like tissue grows into the muscle of the womb (the myometrium). This can make the womb larger, heavier, and feel more tender.
Adenomyosis is most often diagnosed in people in their thirties and forties, but we’re increasingly seeing it identified earlier thanks to better imaging and more awareness.
The symptoms can be very similar, which is why people are often told they “Just have bad periods” for years.
Both endometriosis and adenomyosis can cause:
The overlap doesn’t stop there. Research suggests that up to 80% of women with endometriosis also have adenomyosis. So, for many, it’s not an “either/or”, it’s both.
While there’s a lot of crossovers, some symptoms lean more strongly one way than the other.
Endometriosis is more likely to cause:
Adenomyosis is more likely to cause:
Diagnosis is where things start to diverge.
Endometriosis
You can learn more about endometriosis diagnosis by clicking here
Adenomyosis
Because adenomyosis affects the womb muscle itself, it tends to show up more clearly on scans than endometriosis does.
You can learn more about adenomyosis by clicking here
Both conditions can affect fertility, but in different ways. Pain and heavy bleeding can sometimes make sex difficult, especially around ovulation.
Endometriosis may interfere with ovulation, egg quality, the womb lining, or the movement of the egg and sperm through the fallopian tubes. It is also linked to a slightly higher risk of miscarriage and ectopic pregnancy, particularly in more severe cases.
Adenomyosis can affect how the womb contracts and how well an embryo implants and grows. Some studies suggest it may also increase the risk of miscarriage.
Having one, or both, does not mean pregnancy is not possible. Many women with endometriosis or adenomyosis conceive naturally or with support. But it does mean that understanding what is going on inside your body is important, especially if you are trying to conceive now or thinking about the future.
Endometriosis and adenomyosis often exist together, and their treatments can overlap. But knowing exactly what is going on inside your body allows care to be more targeted and individualised.
For example, it can influence decisions around pain management, hormonal treatment, surgery, and the timing of fertility support. It also helps set realistic expectations about symptom control and pregnancy outcomes, rather than leaving you wondering why things are not improving.
If both conditions are present but only one is recognised, symptoms may persist and the bigger picture can be missed. A clear diagnosis helps avoid years of second-guessing and trial-and-error approaches.
Most importantly, it validates what you are feeling. This is not “just a bad period”. If your symptoms are affecting your life, they deserve proper investigation and a plan that is built around you.
Living with chronic pelvic pain can wear you down. When conditions overlap, it can feel even more confusing. But with better awareness and the right investigations, answers are possible.
If your symptoms don’t quite fit in one box, or treatments haven’t helped as expected, it may be time to ask whether endometriosis, adenomyosis, or both could be part of the picture. Remember, you’re not being difficult when you’re advocating for yourself.