The word “hysteria” is used today to describe the expression of out-of-control emotions, but it was originally coined in the fifth century B.C. by Hippocrates, the Greek physician and philosopher. He believed that a woman who exhibited signs of extreme distress was afflicted by her uterus roaming about her body — naming the condition “hysteron,” after “hystera,” the Greek word for uterus, according to a history of the term.
Over the centuries, hysteria has been attributed to a range of causes, from an inadequate sex life to demonic possession.
And although the understanding of hysteria has evolved over millennia, it was still classified as a mental health condition by the American Psychiatric Association until 1980.
So, it comes as no surprise to Jocelyn Fitzgerald, MD, a urogynecologist, pelvic-reconstruction surgeon, and assistant professor at the University of Pittsburgh School of Medicine, that recent research suggests that women’s health complaints — and pain in particular — are sometimes misunderstood and dismissed by clinicians.
For example, one study found that young women with chest pain waited longer, on average, to be seen in the emergency department than young men who reported the same symptoms. The Centers for Disease Control and Prevention updated its guidelines in 2024 to recommend that clinicians offer their patients pain medication for insertion of intrauterine contraceptive devices (IUDs) after women posted about their pain experiences on social media. And little is understood about fibromyalgia, a condition characterized by generalized pain, fatigue, and cognitive problems that is diagnosed mostly in women.
Fitzgerald works with patients who have endometriosis. A condition in which the uterine lining grows outside the uterus, endometriosis can produce a variety of symptoms, including pain. It’s believed to affect about 1 in 10 women of reproductive age, but a proper diagnosis can take seven to 10 years, thus delaying treatment.
“It’s an extremely under-researched and very poorly understood disease,” Fitzgerald says. “[Historically, it was] probably most commonly described as female hysteria. [This shows] historic gaslighting and labeling of women as being crazy.”
In general, women’s health has been under-researched. In the United States, women were rarely included in clinical trials until 1993 and remain underrepresented in studies.
When it comes to pain, a symptom that has no objective measures and may be influenced by biological, psychological, and sociological factors, understanding sex differences is particularly complicated.
“Women’s pain has been very under-recognized or dismissed to be psychological in nature, which has led to inequitable pain care,” says Emily J. Bartley, PhD, an assistant professor at the University of Florida College of Dentistry who studies chronic pain. “It’s not just something that is in somebody’s head. Pain is real.”
Biological factors
The experience of pain can differ from person to person, but a body of research suggests that biological sex characteristics influence the processing of pain.
For instance, multiple studies have found that sex hormones (including testosterone and estrogen) influence pain, explains Rui Li, PhD, a pain epidemiologist and research assistant professor in the Department of Anesthesiology and Pain Medicine at the University of Washington School of Medicine and a principal investigator at Seattle Children’s Research Institute.
In particular, some data demonstrate that testosterone reduces pain intensity, with effects seen as early as at the onset of puberty, according to Li’s research. She and her team analyzed data from a large, multicenter study on adolescents and found that, over the course of a year, 10- and 11-year-old boys who were pain-free at the beginning of the study and had higher levels of testosterone at the one-year follow-up appointment were less likely to report pain than boys with lower levels of testosterone.
Even in controlled laboratory settings, studies suggest that when men and women are exposed to the same trigger for painful sensations, such as cold, heat, or pressure, women tend to express a higher level of pain.
Research shows that the endogenous opioid system, which is a neurochemical network responsible for the modulation of pain and stress, operates differently in men than in women. These differences seem to make opioid medications less effective at pain relief for women. One study reported that the women in the cohort needed, on average, 30% higher doses of morphine than men to achieve a similar level of reported relief.
And though researchers have documented that opioid use decreases testosterone levels in men, little is known about the impact of long-term opioid use by women, including on their bone density and mental health, says Akiko Okifuji, PhD, a professor of anesthesiology in the Division of Pain Medicine at the University of Utah.
Some preliminary research on rodents suggests that microglia, a type of immune cells that protect the brain from pathogens, participate in the regulation of pain among males but not females. Another study reported that drugs that target the microglia in females may help increase the effectiveness of opioid medication for pain relief.
Other research with rodents suggests there are sex differences at a genetic level that could affect pain modulation, according to the International Association for the Study of Pain. The sex differences associated with these mechanisms are poorly understood, partially because, until recently, researchers often excluded female rodents from lab studies because of hormonal fluctuations related to the menstrual cycle.
Psychosocial factors
While Bartley emphasizes that pain isn’t “just something that is in somebody’s head,” that doesn’t mean that psychological factors are unrelated to the subjective experience of pain.
“There are various psychological and sociological influences, and these factors can alter the experience of and response to pain,” Bartley says. “There’s a lot of research looking at how psychological factors such as anxiety and depression often coexist with chronic pain and can amplify the experience.”
Okifuji studies fibromyalgia and has been trying to understand the mechanisms that result in chronic pain, particularly among women. The research team considered the role of sex hormones in fibromyalgia but didn’t find conclusive evidence of a connection.
“We are now considering pain, particularly chronic pain, to be a bio-psycho-social phenomenon,” she says. “Our life experience seems to come into play. That probably influences how our bodies process noxious stimulation.”
There’s also evidence that, beyond biological sex, gender can also influence a person’s expression of pain. Biological sex is defined by a person’s chromosomes and sex hormones, and gender is defined as the social and cultural characteristics associated with being a man or a woman.
Bartley says that societal gender roles can impact how a person might cope with their pain.
“Women tend to be more emotionally focused, seek social support, and use more positive self-talk,” she says. “Men tend to use more distraction and avoidance behaviors, which can lead to more negative outcomes.”
While women report higher rates of chronic pain, men are overrepresented among “deaths of despair,” such as by suicide or substance abuse.
Social and environmental factors may also intensify the experience of pain.
Studies have reported that experiences of childhood adversity, such as abuse, neglect, or experiencing or witnessing other traumatic events, significantly increase the risk of chronic pain later in life. Experiencing discrimination, poverty, and other societal adversity may increase the likelihood of reporting chronic pain as well.
Because multiple factors may contribute to an individual’s pain experience, Bartley says that patients should have access to a multidisciplinary medical team that can approach the problem from different angles.
While exploring all medical options, clinicians can also direct their patients to resources that can increase resilience against pain, including physical therapy, psychological counseling, mindfulness exercises, yoga, and social supports, she says.
“As a medical profession, we must step outside the biomedical model and look at [pain] more holistically,” Bartley says.
