Pain in Women
Chronic pain is defined as pain lasting for more than 6 months.
In the UK alone, approximately 7.8 million people live with chronic pain with, at any time, over a third of households containing someone in pain.
Our work aims to optimise pain relief and quality of life for women with chronic pain by improving our understanding of the mechanisms generating pain in women and the interaction between hormones and pain.
what we do
Chronic pain is defined as pain lasting for more than 6 months. In the UK alone, approximately 7.8 million people live with chronic pain with, at any time, over a third of households containing someone in pain. Women suffer with almost all chronic pain conditions to a much greater extent than men. Additionally, they also suffer from female-specific pains; particularly in their pelvis, including period pain (dysmenorrhoea) and the pains associated with diseases such as endometriosis. Unfortunately, it is frequently difficult to treat chronic pain and attempts at finding new drugs have not usually been successful. Our work focuses on two aspects of pain specific to women. Firstly, we are interested in better understanding the mechanisms generating and maintaining pain in gynaecological pain conditions such as dysmenorrhoea and endometriosis. Secondly, we are investigating the relationship between steroid hormones and pain. In the long-term we hope to be able to optimise both analgesia and quality of life for women with chronic pain whatever its original cause.
Epidemiology of chronic pelvic pain:
Our past work has shown that chronic pelvic pain (constant or intermittent lower abdominal pain unrelated to periods or intercourse, lasting for six months or more) is common, with up to 24% of women reporting having experienced such pain in the UK. The extent to which the lives of women are affected by the pain varied widely, and our studies of general practice records showed that annually approximately 4% consult a GP for their symptoms. Most women with chronic pelvic pain also reported pain with periods and intercourse, and many had additional bowel or bladder related symptoms, which complicated differential diagnosis and meant that over time they often received several ‘diagnoses’ including irritable bowel syndrome, cystitis, endometriosis, chronic pelvic inflammatory disease, and ‘stress’.
Associations of dysmenorrhoea:
Period pain (dysmenorrhoea) is common. Our work combined brain imaging (functional magnetic resonance imaging (fMRI)) with hormone levels and psychological measures to investigate the long-term consequences of experiencing pain for one or more days every month. Even though the women we studied had no pain outside of their periods we found that they showed many of the long-term changes seen in other chronic pain conditions. Thus, even though they were psychologically healthy (normal levels of anxiety and depression), they were more sensitive to experimental pain, showed altered brain processing of these painful stimuli and had reduced levels of cortisol (a stress hormone) in their blood. In combination with other recent studies showing altered brain structure in women with dysmenorrhoea our findings contributed to the reclassification of dysmenorrhoea as a chronic pain condition in the most recent IASP taxonomy of pain.
The influence of sex hormones on acute pain in healthy women:
Even non-gynaecological pain conditions frequently show variation in symptom severity with the menstrual cycle. We have combined fMRI with measures of blood hormone levels to investigate the relationship between specific hormones and the response to painful stimuli and to try to understand the mechanisms underlying these findings. Our results suggest that steroid hormones interact with known internal pain-modulating mechanisms. For example, when estrogen levels are low it appears that testosterone is important in reducing pain, whilst when estrogen levels are high progesterone reduces the unpleasantness of a pain experience. We are now investigating whether these relationships are the same for women with chronic pain conditions.
The Advanced Pain Discovery Platform (APDP)
The Advanced Pain Discovery Platform (APDP) is a UK-based network of scientists, clinicians and patients who are coming together to try and deliver new breakthroughs in understanding human pain. Chronic pain is one of the greatest unmet needs in healthcare. It is the leading global cause of disability and carries an enormous socioeconomic cost in the UK and worldwide. But progress in delivering new treatments has been difficult and slow. Katy Vincent is leading a project focusing on pain in women, who are more likely to develop almost all types of chronic pain than men are. Her research aims to understand whether period pain during adolescence increases the risk of developing chronic pain as a young woman, and to identify the mechanisms that underlie this risk from childhood through to adulthood. In collaboration with Krina Zondervan, Mina Fazel, Kate Stein, Sharon Dixon, MaryAnn Noonan and colleagues from Endometriosis UK and Bristol University, she will be combining both laboratory and clinical epidemiological data in a wide variety of contexts. Prof Vincent commented:
"We are really excited for the opportunity this funding gives us to better understand period pain in teenagers. Severe period pain is incredibly common yet is frequently dismissed as a normal part of being a woman. We hope to be able to better understand who is at risk of developing severe period pain soon after their periods start and determine whether experiencing period pain as a teenager increases the risk of other chronic pain conditions in adulthood. Ultimately we hope to use this information to reduce pain and improve quality of life for both teenagers and adult women."