Gender Differences in Processing and Perceiving Chronic Pain

Pain is an integral part of the human experience, subjective in nature and can only be perceived by the person experiencing the pain. Pain can be described as a “an unpleasant sensory and emotional experience associated with actual or potential tissue damage” according to the Internal Association for the Study of Pain. However, with chronic or persistent pain symptoms, emerging evidence in the study of neuroscience has consistently demonstrates that pain is no longer a symptom of tissue pathology but an altered, misinterpretation by the central nervous system. This complex neurological processing can be greatly affected by other factors including emotions, memories, social and environmental stimuli. 

According to pain science literature, pain can be classified into four categories: nociceptive, neuropathic, inflammatory and dysfunction. 

Nociceptive pain is the pain that we all know ranging from ankle strain/sprains, joint pain (somatic) to stomach aches (visceral). Within our soft tissues and joints are free nerve endings called nociceptor that detect noxious, or painful stimuli. Nociceptive pain is part of our survival mechanism alerting us to get help when there is physiological danger; however, can be considered maladaptive if pain continues after tissue healing has taken placed. Neuropathic pain occurs in response to damage to the nervous system itself either central or peripheral. This pain can often be described as stabbing, electrical or burning, such as radiating pain into the lower extremity from a lumbar disc herniation. Phantom pain limb syndrome can also be regarded as neuropathic pain where pain extends beyond the actual tissue healing phase, now involving pathological adaptations in the somatosensory nervous system. Inflammatory pain is associated with increased sensitivity due to tissue damage as a result of an inflammatory response, such as an infection. Dysfunctional pain refers to an increased level of sensitivity without an actual peripheral stimulus and minimal tissue pathology.

Various studies on epidemiology have consistently demonstrated that women are much more likely to experience both acute and chronic pain, more prone to use medications and more likely to seek treatment to alleviate their painful syndromes. Women in general often reports a higher rate of both acute and chronic pain including post-operative pain, temporal-mandibular joint pain (TMJ), migraine pain headaches, fibromyalgia symptoms, irritable bowel syndrome (IBS), and other chronic pain related symptoms. 

Hormones

One of the reasons that account for these gender differences in pain perception is the influence of hormonal contributions. Women are more vulnerable to hormonal fluctuations within their lifespan, including during and after pregnancy, peri and post menopausal, and monthly during their reproductive years. Levels of estrogens, progesterone and testosterone differ significantly between men and women and contribute to the presentation of clinical pain. According to studies, testosterone and progesterone are both associated with reducing pain threshold, progesterone has been shown to be anti-inflammatory, neuroprotective, and generally analgesic. On the other hand, studies of the effects of estradiol on clinical pain is more complex where it can be both anti-nociceptive (inhibits pain) and pro-nociceptive (heightens pain). For example, during the follicular phase of the menstrual cycle, when levels of estradiol and progesterone are low to moderate, women in the clinical studies demonstrate a heightened level of sensitivity to mechanical, thermal, and ischemic muscle pain. 

Within the transexual community, about 55% of those with chronic pain who transitioned from female-to-male reported a reduction in pain following testosterone treatment. The opposite of that is true from male-to-female receiving estrogen anti-androgen treatment, about 23% of the population reported greater sensitivity to pain. These studies suggest that testosterone can be analgesic in nature. 

Neuroscience 

The subjective experience of pain is modulated by a model called diffuse noxious inhibitory control (DNIC). This endogenous pain modulatory pathway focuses on a specific painful stimuli that affects one part of the body while inhibiting another part, cancelling out excessive “noise”. The inefficiency of this pathway is thought to contribute to central pain sensitization, often associated with chronic painful conditions, such as fibromyalgia. Past studies seems to suggest gender differences in this pain modulatory pathway, where DNIC is better regulated in men than women. 

Psychosocial 

Catastrophizing is the cognitive dialogue that something is worse than what it actually is, which has been strongly associated with chronic or persistent painful syndrome. Previous studies have shown that women with musculoskeletal conditions were more like to engage in catastrophizing behaviors than their male counterparts. Exposure therapy along with exercise training were both found to be helpful in chronic low back conditions in the reduction of pain and catastrophizing behavior. 

In our society, we expect that men in general should have greater pain tolerance as the ability to tolerate pain is correlated with the masculine ideal. We expect men to be stoic and discourage the expression of pain, as such men are less likely to seek treatment for chronic pain symptoms. The ability to accept and express pain as part of normal life is more permissible with the female gender norm, as childbirth, premenstrual and menstrual symptoms are natural occurrences within her lifespan. 

Chronic pain is a complex subject and our understanding continues to evolve in both clinical and research setting. Understanding sex differences has important implications when interacting with both genders in a clinical or rehabilitative setting, the topic is wide and can only be elucidated briefly here, a curious mind can continue to investigate further. 

References: 

Fillingim RB, King CD, Ribeiro-Dasilva MC, Rahim-Williams B, Riley JL 3rd. Sex, gender, and pain: a review of recent clinical and experimental findings. J Pain. 2009;10(5):447‐485. doi:10.1016/j.jpain.2008.12.001

Fillingim RB. Sex differences in analgesic responses: Evidence from experimental pain models. Eur J Anaesthesiol Suppl. 2002;26:16–24.

Fillingim RB. Sex, gender, and pain: Women and men really are different. Curr Rev Pain. 2000;4(1):24–30.

Schertzinger M, Wesson-Sides K, Parkitny L, Younger J. Daily Fluctuations of Progesterone and Testosterone Are Associated With Fibromyalgia Pain Severity. J Pain. 2018;19(4):410‐417. doi:10.1016/j.jpain.2017.11.013

Aloisi AM, Bachiocco V, Costantino A, Stefani R, Ceccarelli I, Bertaccini A, Meriggiola MC. Cross-sex hormone administration changes pain in transsexual women and men. Pain. 2007;132:S60–67.

Ellingson LD, Stegner AJ, Schwabacher IJ, Lindheimer JB, Cook DB. Catastrophizing Interferes with Cognitive Modulation of Pain in Women with Fibromyalgia. Pain Med. 2018;19(12):2408‐2422.

Unruh AM. Gender variations in clinical pain experience. Pain. 1996;65(2-3):123–67.