Long considered a mysterious disease, endometriosis affects approximately 10% of women of reproductive age worldwide. Pelvic pain, extremely painful periods, chronic fatigue… The symptoms can be debilitating and last for years. But a question remained: why is this pain sometimes so intense, even when the lesions are barely visible or have been removed?
A new scientific study now provides major answers by showing that pain does not come only from the lesions themselves, but from a more global disruption of the nervous system.
Chronic inflammation that “sensitizes” the body
Researchers have identified a key phenomenon: repeated episodes of retrograde menstruation (when menstrual blood flows back into the abdominal cavity) cause persistent inflammation in the pelvis.
This inflammation continuously activates the immune system, with increased production of inflammatory molecules. Result: the nerves become more and more sensitive to stimuli, a bit like a sound volume that we gradually increase.
Over time, this hypersensitivity is no longer limited to the pelvic area. It can extend to other parts of the body, explaining why some patients feel diffuse or even generalized pain.
The brain also involved in pain
One of the most important discoveries concerns the role of the brain. The study shows that chronic inflammation eventually changes the way the central nervous system functions, a phenomenon called “central sensitization.”
Concretely, certain cells in the brain and spinal cord become excessively activated, amplifying pain signals. Even in the absence of significant lesions, the brain continues to perceive — and amplify — pain.
This mechanism explains why pain may persist after surgery or be disproportionate to the extent of the disease.
Towards new treatment avenues
These results profoundly change the understanding of endometriosis. They suggest that treatments should not only target the lesions, but also the inflammation and the nervous system.
Some drugs tested in the study, such as hormonal treatments or immunomodulators, have shown the ability to reduce pain by acting on these neuroinflammatory mechanisms.
Ultimately, this approach could provide better relief to patients, particularly those for whom current treatments remain insufficient.
This scientific advance marks an important step: it confirms that endometriosis is a complex disease, involving both the immune system and the brain. By better understanding the mechanisms of chronic pain, research paves the way for more effective treatments — and above all, for better recognition of patients’ suffering.