When people talk about painful periods, two conditions often come up: endometriosis and adenomyosis.
They sound similar, they involve similar tissue and they even share many symptoms. And because of that, they’re often confused with each other.
But they’re not the same condition and understanding the difference can help people recognise symptoms earlier and seek the right care.
Let’s break it down simply:
What Is Endometriosis?
Endometriosis is a chronic inflammatory condition where tissue similar to the lining of the uterus (the endometrium) grows outside the uterus.
This tissue can grow on areas like:
- the ovaries
- fallopian tubes
- bowel or bladder
- pelvic lining
- and in rare cases, organs beyond the pelvis
Each month, this tissue responds to hormonal changes just like the uterine lining does. But because it’s outside the uterus, the body can’t shed it normally, which can cause inflammation, scarring and pain.
Endometriosis affects roughly 1 in 10 women and people with periods worldwide.
(Source: World Health Organisation)
What Is Adenomyosis?
Adenomyosis involves similar tissue, but it grows inside the muscle wall of the uterus.
Instead of growing outside the uterus like endometriosis, the endometrial-like tissue grows within the uterine muscle (the myometrium).
This can cause the uterus to become enlarged or thickened and can lead to heavy, painful periods.
Adenomyosis was once thought to be a subtype of endometriosis, but medical research now recognises it as a separate condition, though the two can occur together.
Key Difference Between Adenomyosis and Endometriosis
The biggest difference between the two conditions is where the tissue grows.
Endometriosis
→ tissue grows outside the uterus
Adenomyosis
→ tissue grows within the uterine muscle
Despite this difference, both conditions can cause chronic pelvic pain, painful periods, and inflammation. And many people actually have both conditions at the same time.
Symptoms of Adenomyosis vs Endometriosis
There’s a lot of overlap between the symptoms, which is one reason diagnosis can be difficult.
Adenomyosis symptoms
- Heavy menstrual bleeding
- Painful periods
- Enlarged or tender uterus
- Bleeding between periods
- Pain after sex
- Chronic pelvic pain
Endometriosis symptoms
- Severe period pain
- Pain during sex
- Pelvic pain outside of periods
- Painful bowel movements or urination
- Fatigue
- Nausea or digestive symptoms during periods
Both conditions can significantly impact quality of life, work, relationships and mental health. (Source: NHS)
Who Is Most Likely to Develop Adenomyosis?
Adenomyosis tends to be diagnosed more often in people who:
- are in their 30s or 40s
- have had children
- previously experienced endometriosis
However, improved imaging technology means doctors are now recognising it earlier in life as well.
Why These Conditions Are Often Missed
One of the biggest challenges with both adenomyosis and endometriosis is diagnosis.
Symptoms are frequently dismissed as “just bad periods”. On average, endometriosis can take 7–10 years to diagnose.
Adenomyosis can also be difficult to identify because the condition often requires imaging scans or surgical pathology to confirm.
Common diagnostic tools include:
- pelvic exam
- ultrasound
- MRI scans
- laparoscopy (for endometriosis)
(Source: Endometriosis UK)
Treatment Options
There is currently no universal cure for either condition, but there are ways to manage symptoms.
Treatment may include:
- Pain management
- Hormonal treatments and contraception
- Surgery
Treatment options depend heavily on:
- symptom severity
- age
- fertility goals
- overall health
(Source: NHS)
Lifestyle Support and Symptom Management
Because both conditions involve inflammation, lifestyle factors may influence symptoms.
Many people find symptom relief through:
- anti-inflammatory nutrition approaches
- regular gentle movement
- stress management
- sleep support
Working with healthcare professionals like dietitians or pelvic health specialists can help create a personalised approach.
Importantly, there is no single diet or supplement proven to cure these conditions, and what helps one person may not help another.
Why Awareness Matters
Adenomyosis and endometriosis are both common, but they are still under-diagnosed and under-researched.
Raising awareness helps people recognise symptoms earlier, seek support sooner and advocate better for their health.
Painful periods should never be dismissed as something you just have to live with. Your body deserves to be listened to. If something about your cycle feels off, trust that instinct. You know your body better than anyone.
