Everything you need to know about Endometriosis | Beavida

Health Hormones Menstruation

8 min read

Everything you need to know about Endometriosis

Endometriosis is a chronic, systemic inflammatory condition in which tissue resembling the endometrium develops outside the uterus. It is now understood as a multi-layered disease involving hormonal dysregulation, immune activation, and neuro-sensitisation rather than a purely structural pelvic disorder.

At its core, endometriosis is driven by an imbalance between oestrogen-driven inflammatory activity and impaired progesterone signalling. These hormonal dynamics interact with the immune system and nervous system, creating a feedback loop that can intensify pain, fatigue, and cyclical symptom flares over time.

What is endometriosis?

Endometriosis occurs when endometrial-like tissue is present outside the uterine cavity, most commonly within the pelvic region. These lesions are biologically active and hormonally responsive, but they are not identical to normal endometrial tissue.

In a healthy menstrual cycle, oestrogen stimulates growth of the uterine lining, while progesterone stabilises and limits excessive proliferation. In endometriosis, this balance is disrupted. Ectopic lesions often exist in a state of relative oestrogen dominance due to local oestrogen production within the lesions themselves, combined with reduced responsiveness to progesterone.

This creates a self-sustaining inflammatory environment. Lesions release prostaglandins and cytokines, which recruit immune cells and increase nerve sensitivity. Over time, this leads to chronic inflammation, fibrosis, adhesions, and changes in pain processing within the central nervous system.

The symptoms of endometriosis

Symptoms arise from a combination of hormonal dysregulation, inflammatory signalling, mechanical distortion from adhesions, and nervous system sensitisation. Because these systems overlap, symptoms often extend beyond the pelvis and fluctuate across the menstrual cycle.

Painful periods

Menstrual pain in endometriosis is typically severe and progressively worsening. It is driven by increased prostaglandin production, which causes intense uterine contractions and reduced blood flow to uterine tissue, creating ischaemic pain.

At the same time, ectopic lesions respond to hormonal fluctuations and release inflammatory mediators that sensitise nearby nerves. This leads to amplified pain perception, often disproportionate to the amount of visible tissue involvement.

Chronic pelvic pain

Chronic pelvic pain develops when repeated inflammatory signalling leads to both peripheral nerve sensitisation and central nervous system amplification. Over time, the nervous system becomes hyper-responsive, meaning that pain can persist even outside of active inflammatory cycles.

Adhesions also contribute by restricting organ movement, creating mechanical tension and traction on surrounding tissues, which further activates pain pathways.

Pain during or after sex

Pain during intercourse is often associated with deep infiltrating lesions affecting pelvic structures such as ligaments or the rectovaginal space. Mechanical pressure can directly stimulate inflamed tissue.

In addition, long-standing pain often leads to pelvic floor muscle hypertonicity. This protective muscle guarding reduces tissue flexibility and increases sensitivity, meaning that even normal movement can become painful.

Bowel and bladder symptoms

When lesions affect the bowel or bladder, they interfere with smooth muscle function and local nerve signalling. Inflammatory mediators disrupt normal motility and visceral sensitivity, which can lead to cyclical bowel changes, urinary urgency, or discomfort.

Because these symptoms fluctuate with hormonal cycles, they are frequently mistaken for functional gastrointestinal disorders such as IBS.

Gastrointestinal symptoms and bloating (“endo belly”)

Bloating and digestive discomfort arise from a combination of inflammatory signalling, altered gut motility, and visceral hypersensitivity. Oestrogen fluctuations can influence fluid retention and gut function, while inflammatory mediators affect the enteric nervous system.

Adhesions near the bowel can also physically restrict movement, contributing to cyclical distension and discomfort.

Heavy or irregular menstrual bleeding

Heavy or irregular bleeding is often linked to underlying hormonal imbalance rather than direct bleeding from endometriotic lesions themselves. In many individuals with endometriosis, progesterone signalling is impaired due to reduced receptor responsiveness, meaning its stabilising effect on the uterine lining is weakened.

Under normal conditions, progesterone helps regulate the timing and structure of the menstrual cycle by organising the endometrium into a stable, receptive state before it is shed in a controlled way. When this signalling is disrupted, the endometrium may develop in a more disorganised and uneven pattern.

At the same time, oestrogen-driven proliferation continues relatively unchecked. This can lead not only to a thicker uterine lining, but also to asynchronous growth and breakdown, where different areas of the endometrium respond differently to hormonal signals.

As a result, irregular bleeding may occur in several ways:

Unpredictable cycle timing, due to disrupted hormonal feedback between the ovaries and brain
Spotting between periods, caused by unstable areas of the endometrial lining breaking down prematurely
Prolonged bleeding, where shedding is incomplete or extended due to poor structural organisation of the tissue

Inflammation further contributes to this process by affecting blood vessel integrity and repair mechanisms within the endometrium, making bleeding more likely to be prolonged or inconsistent.

Coexisting conditions such as adenomyosis can amplify these effects by increasing the surface area of hormonally responsive tissue and further disrupting normal uterine contractility, which is needed to efficiently shed the lining.

Fatigue

Fatigue is closely tied to systemic inflammation rather than physical exertion alone. Cytokines produced in chronic inflammatory states influence brain regions involved in energy regulation, leading to reduced drive and persistent exhaustion.

This is compounded by sleep disruption due to pain, hormonal fluctuations, and, in some cases, iron deficiency secondary to heavy bleeding.

PMS-related symptoms

Many individuals with endometriosis experience intensified premenstrual symptoms, which may overlap with or amplify typical PMS. These symptoms can include mood changes, irritability, headaches, breast tenderness, and dizziness.

Dizziness in particular can arise from several interconnected mechanisms. Hormonal fluctuations in oestrogen and progesterone affect vascular tone and fluid regulation. A drop in oestrogen in the late luteal phase can influence blood vessel stability and autonomic nervous system balance, which may contribute to light-headedness or a sense of instability.

Inflammation also plays a role. Elevated prostaglandins and cytokines can influence neurological signalling and blood pressure regulation. In some cases, iron deficiency caused by heavy menstrual bleeding may further contribute to dizziness through reduced oxygen delivery to tissues.

Additionally, blood sugar variability and stress-related autonomic nervous system activation can amplify these sensations, making these symptoms more noticeable in the premenstrual phase.

Fertility challenges

Fertility may be affected through multiple pathways, including anatomical distortion from adhesions, inflammatory effects on egg quality, altered tubal function, and reduced endometrial receptivity. However, fertility outcomes vary widely depending on disease severity and individual physiology.

Medical approach to endometriosis

Medical management aims to reduce inflammation, suppress oestrogen-driven lesion activity, and manage pain sensitisation. Treatment response varies significantly due to differences in hormone receptor sensitivity and immune system behaviour.

Non-steroidal anti-inflammatory drugs (NSAIDs)
These reduce prostaglandin production by inhibiting cyclooxygenase enzymes. This decreases inflammatory pain signalling and uterine hypercontractility. They are most effective for cyclical pain but do not alter underlying disease processes.
Hormonal therapies (combined contraceptives and progestins)
These aim to reduce oestrogen stimulation of lesions by suppressing ovulation or stabilising hormonal fluctuations. However, effectiveness can vary due to progesterone resistance, where endometriotic tissue shows reduced progesterone receptor activity. This limits the anti-inflammatory and stabilising effects of progestin-based treatments in some individuals.
GnRH agonists and antagonists
These suppress ovarian hormone production, creating a low-oestrogen state that reduces lesion activity. While often effective for symptom control, they may produce hypo-oestrogenic side effects such as reduced bone density, hot flushes, and mood changes.
Surgical excision (laparoscopy)
Surgery removes visible lesions and adhesions, which can reduce pain and improve function. However, it does not address underlying hormonal or immune dysregulation, meaning recurrence is possible over time.

Holistic support and system regulation

Supportive strategies focus on reducing inflammatory load, modulating nervous system sensitivity, and improving hormonal resilience.

Dietary and inflammatory modulation
Nutritional patterns may influence prostaglandin production, oxidative stress, and immune activity. Diets rich in omega-3 fatty acids, fibre, and polyphenols may help reduce inflammatory signalling, while highly processed foods may increase systemic inflammation. The gut microbiome also plays a role in oestrogen metabolism, influencing hormonal balance indirectly.
Stress physiology and nervous system regulation
Chronic stress activates the hypothalamic-pituitary-adrenal axis, which can amplify inflammatory signalling and increase pain sensitivity through central sensitisation. Over time, the nervous system may become more reactive to normal physiological stimuli, increasing symptom intensity.
Pelvic floor function and physiotherapy
Chronic pain often leads to protective pelvic floor muscle tension. This sustained contraction reduces flexibility and increases pain sensitivity. Physiotherapy aims to restore normal muscle function and reduce pain-related guarding patterns.
Movement and circulation support
Gentle, consistent movement supports circulation, lymphatic drainage, and endorphin release. This can help modulate pain perception and reduce stiffness without triggering symptom flares.
Sleep and circadian rhythm support
Disrupted sleep increases inflammatory sensitivity and reduces pain thresholds. Stabilising sleep patterns supports hormonal regulation and improves resilience to fatigue and pain.

Conclusion

Endometriosis is a complex condition shaped by hormonal imbalance, immune activation, and nervous system sensitisation. Oestrogen-driven inflammation combined with impaired progesterone signalling contributes to persistent lesion activity and symptom variability.

Symptoms such as pelvic pain, digestive disturbance, heavy or irregular bleeding, fatigue, PMS, and fertility challenges arise from overlapping biological systems rather than a single cause.

Understanding these interconnected mechanisms helps explain why symptoms can vary so widely and why management often requires a combined medical and systemic approach rather than a single treatment pathway.