Javier Rivera
This article is an excellent review describing the main findings regarding some of the pathophysiological mechanisms involved in primary visceral chronic pain. It is based on the established evidence that this type of pain is much more common in women, and this study primarily analyses the role played by different hormones in this process.
Hormonal influence shows a close correlation with pain and its chronicity via mechanisms of central sensitisation. Oestrogen levels in women increase visceral sensitivity via specific receptors in the internal organs. They influence the gut microbiome by inducing the production of certain metabolic products by the microbiome itself, which are responsible for the development of hypersensitivity to pain. Oestrogens also influence pain processing in various structures of the nervous system and modulate the activation of neuroimmune circuits in response to painful stimuli through the activation of immune cells, which differ between the sexes.
In other primary chronic pain syndromes — such as fibromyalgia, headaches and chronic pain associated with osteoarthritis, which are also much more common in women — the scientific evidence regarding the pathophysiological mechanisms involved is more limited, but they are likely to be the same and also attributable to hormonal differences.
Research into primary chronic pain is currently a very active field. Chronic pain is a condition that affects more than 20 per cent of the general population, with a particularly high prevalence amongst women, amongst whom the existence of this condition and the serious impact it has on their quality of life are often overlooked.
Unfortunately, current treatments for chronic pain are unable to manage this condition satisfactorily; however, new findings regarding the pathophysiological mechanisms involved in this process open the door to promising new strategies for the treatment of primary chronic pain.