Why Endometriosis Is More Than a Gynaecological Condition

March is Endometriosis Awareness Month, a time when conversations often focus on the reproductive aspects of the disease.

Yet the more we learn about endometriosis, the clearer it becomes that it is far more than a gynaecological condition.

Last month I had the privilege of presenting “non‑pharmacological interventions in endometriosis” to future pharmacists at the University of Manchester. The discussion explored how nutrition, lifestyle medicine, nervous system regulation and metabolic health can complement conventional medical care.

Endometriosis is increasingly recognised as a systemic condition involving inflammation, immune signalling, hormone metabolism and the gut microbiome. This broader understanding mirrors what many women experience in clinical practice: symptoms rarely exist in isolation. They interact with other physiological systems, including immune reactivity, stress physiology and gut health.

What is Endometriosis?

Endometriosis occurs when tissue similar to the lining of the uterus grows outside the womb. 

These lesions most commonly appear on: 

• the ovaries 

• the pelvic lining 

• the bowel 

• the bladder 

In more complex cases they may extend deeper into the abdominal cavity and, in rare situations, lesions have even been identified in distant organs such as the lungs. 

Symptoms frequently extend beyond menstrual pain and can include: 

• chronic pelvic pain 

• severe menstrual cramps 

• digestive disturbances 

• fatigue 

• sleep disruption 

• painful intercourse 

• fertility challenges 

Endometriosis affects an estimated one in ten women of reproductive age, yet diagnosis often takes several years. 

If you would like a broader overview of how the condition develops and the different ways it can present clinically, you may find helpful my earlier article “Understanding Endometriosis – Symptoms and Root Causes” where I discuss the diagnostic journey and the biological mechanisms that underpin the condition. 

Symptoms of Endometriosis Beyond Pelvic Pain

Although endometriosis is commonly associated with menstrual pain, many women experience symptoms that affect multiple body systems. 

These may include: 

• digestive symptoms such as bloating or IBS-like discomfort 

• fatigue and low energy 

• brain fog 

• inflammatory symptoms 

• pelvic pressure 

• pain during intercourse 

• difficulty concentrating 

• heightened sensitivity to stress 

Understanding these systemic symptoms is one reason why endometriosis is increasingly recognised as a whole-body inflammatory condition rather than purely a reproductive disorder. 

Inflammation and Immune Signalling

One of the defining biological features of endometriosis is persistent inflammation. 

Researchers have identified increased levels of inflammatory molecules such as cytokines and prostaglandins in the pelvic environment of women with endometriosis. 

Cytokines are signalling proteins released by immune cells that coordinate immune responses. Prostaglandins are lipid compounds involved in inflammation and pain regulation during the menstrual cycle.  

Elevated levels of these molecules can increase pain sensitivity and contribute to lesion persistence (Bulun, 2019). 

Inflammation does not operate in isolation. It interacts with other immune pathways in the body, particularly those involving mast cells and histamine signalling. 

I explore these mechanisms further in the article “Histamine, Mast Cells and Midlife Reactivity” where I explain how immune signalling can influence inflammatory responses and hormone sensitivity. 

Understanding these immune pathways may help explain why some women with endometriosis experience heightened reactivity to stress, certain foods or hormonal fluctuations. 

How the Immune System Behaves Differently

Several immune cells appear to function differently in endometriosis. 

Macrophages normally help remove damaged tissue and cellular debris. In endometriosis they often become highly activated and release inflammatory mediators that sustain inflammation. 

Natural killer cells help identify and eliminate abnormal cells. Reduced NK cell activity may allow misplaced endometriallike tissue to persist instead of being cleared by the immune system. 

Mast cells release histamine and other inflammatory substances. Increased mast cell activity has been observed in endometriotic lesions and may amplify pain and inflammatory signalling.  

Because mast cells interact closely with the nervous system and immune system, they are increasingly recognised as important players in chronic inflammatory conditions. 

Some researchers have even explored whether endometriosis shares characteristics with autoimmune-like conditions, given the immune dysregulation observed in many patients. 

Hormones and Local Oestrogen Production

Endometriosis is often described as an oestrogendependent condition, but the hormonal picture is more complex than simply having elevated oestrogen. 

Research has demonstrated that endometriotic lesions can produce oestrogen locally through increased aromatase enzyme activity. This allows lesions to stimulate their own growth (Attar & Bulun, 2006). 

At the same time many patients show progesterone resistance, meaning progesterone’s protective antiinflammatory effects may be reduced. This imbalance between oestrogen stimulation and progesterone signalling contributes to the persistence of lesions and ongoing inflammation. 

The Gut-Endometriosis Connection

The gut microbiome plays an important role in immune regulation and hormone metabolism. 

Certain microbes participate in the estrobolome, the microbial network responsible for metabolising and eliminating oestrogen from the body. When this ecosystem becomes disrupted, oestrogen metabolism may also change, potentially contributing to inflammatory signalling. 

Digestive symptoms such as bloating, altered bowel habits or IBS like symptoms are therefore frequently reported in women with endometriosis (Hearn-Yeates et al., 2024). I explore the relationship between gut health and hormonal balance more extensively in the article “Gut Health and Hormone Balance”, which explains how microbial diversity influences oestrogen metabolism. 

Stress Physiology and Chronic Pain

Living with chronic pain can influence the body’s stress response system. 

Persistent inflammatory signalling and repeated pain signals may affect the hypothalamicpituitaryadrenal axis, the hormonal system that regulates stress and energy levels. This phenomenon is known as central sensitization. Over time this can contribute to fatigue, disrupted sleep and difficulty recovering from stress. 

I explore this mechanism in more depth in my article “Tired but Wired – Understanding the HPA Axis“, where I explain how chronic stress physiology can amplify inflammatory conditions and affect energy levels. 

What Emerging Research Is Showing

Recent research continues to deepen our understanding of endometriosis as a systemic inflammatory condition. 

Studies have highlighted several key mechanisms: 

• immune dysregulation involving macrophages and natural killer cells 

• local oestrogen production within endometriotic lesions 

• altered gut microbiome composition 

• neuroinflammatory pathways contributing to chronic pain (Chwertner et al., 2013)

These findings support a broader understanding of systemic inflammation and endometriosis, reinforcing the idea that the condition involves multiple physiological systems rather than reproductive anatomy alone. 

A Whole-Body Perspective

In clinical practice, many women with endometriosis report symptoms that extend well beyond the reproductive system. Fatigue, digestive disturbances, inflammatory symptoms and stress sensitivity often accompany pelvic pain. Understanding these patterns through a systems biology lens can help clinicians explore more comprehensive strategies to support patients alongside conventional treatment as endometriosis is not simply a reproductive condition. 

Hormones, immune signalling, inflammation, gut health and nervous system regulation all interact to influence how the disease develops and how symptoms are experienced. 

Understanding this broader physiological landscape allows women to explore supportive strategies alongside medical treatment. 

Approaches that may complement medical care include dietary interventions that support inflammation regulation, lifestyle strategies that improve sleep and metabolic health, and techniques that support nervous system balance. 

Awareness is important. 

But understanding the biology behind the condition is what ultimately empowers women to navigate it with greater clarity. 

For a broader overview of the condition, you may also find helpful my earlier article on understanding endometriosis symptoms and root causes.