Why Are Migraines More Common With Women Than Men?

If you suffer from migraines, you may have noticed that more of your female friends, family members and coworkers can relate to your disorder than your male associates.

You are not imagining this. Women are three times more likely to experience migraines than men. Additionally, around 25% of all women will experience migraines at some point in their lives.

There are a number of reasons why women are more likely to have to deal with these crippling headaches than their male counterparts.

But this is something that needs to be put in a broader perspective and context in order to be fully understood.

First Of All, It Isn’t Just Migraines That Women Experience More Than Men

Discover in just 7 short questions why you may be experiencing painful migraines and uncover how to alleviate these destabilizing symptoms and return to your normal life. Take The Migraine Quiz Now!  

To begin with, migraines are just one of the pain disorders which are more common among women than men. Some others include:

  • Fibromyalgia
  • Myofascial pain
  • Arthritis
  • Chronic fatigue syndrome
  • Pelvic pain
  • Abdominal pain
  • TMD

Keith A. Yount reports in an issue of Practical Pain Management:

“In double-blind, randomized studies, the female-to-male ratio is 3-to-1 for chronic pain in most of the major head and neck pathologies. However, the actual number of women seeking care is closer to 10-to-1, or even as high as 15-to-1 for some chronic pain clinics. In 2001, the ratio of females-to-males requesting examination at Raleigh Facial Pain Services was 84% and in 2002 it was 80%.”

I will be referring to Yount’s article a lot, as it is a solid, comprehensive summary of a wide range of factors that account for sex differences in the experience of pain.

The reality is also that quite a few of these conditions overlap. For example, it is common for myofascial pain to develop in relation to TMD or fibromyalgia.

Some people also experience more than one type of headache. You might for example have tension headaches which end up setting off migraines.

Secondly, There Are Other Possible Causes of Your Headaches

Speaking of different types of headaches, I have a strong suspicion that many people who believe that they suffer from migraines may actually be experiencing other types of headaches.

Here is how tension headaches and migraines are usually described:

  • Migraines: Moderate to severe unilateral pain with a throbbing quality.
  • Tension-type headaches: Mild to moderate “dull” pain which doesn’t throb, and which feels like a “tight band around the head.”

This may be a good starting point in diagnosing headaches, but it certainly does not tell the full story.

Bonus: Download This 7-Day Headache Reset that will show you how to tackle your worst migraine symptoms quickly.

For around a decade, I assumed that I experience migraines because the pain that I feel is typically unilateral, is often moderate to severe, and sometimes does have a throbbing quality.

There is however such a strong correlation between even my most intense headaches and the trigger points in my muscles that it seems more likely that what I’m experiencing would be more properly termed “myofascial headaches” or something along those lines (perhaps “cervicogenic headaches,” since alignment problems in my bone structure are what led to my muscular issues).

That having been said, for all I know, I do also experience migraines. It is common after all the tension headaches to trigger them.

But all of the symptoms that I have experienced can be caused without migraines. So it seems entirely likely that I have misdiagnosed myself over very long period of time.

Some cases of migraine are cut-and-dried. If for example your headache is accompanied by aura, that is probably a very strong sign that it is indeed a real migraine.

But you would be surprised by some of the symptoms which you might think are only associated with migraine which actually can crop up with other types of headaches.

For example, you might think that nausea is only associated with migraines. But actually, it can be induced by cervicogenic or TMJ pain as well.

Cervicogenic headaches can also lead to sensitivity to light and sound, and even visual problems.

So the bottom line here is that you cannot necessarily make assumptions about your headaches based on your symptoms.

While you may indeed have migraines as you suspect, it is also entirely possible that your headaches stem from other causes.

For this reason, I will be going over not just why women’s bodies prime them for migraine pain, but also for pain disorders in general.

Here Are Some of the Reasons Why Women’s Bodies Are Primed for Pain

woman in pain (knee pain)

1. Hormonal fluctuations can act as a trigger.

First up on the list are fluctuations in hormones. These are experienced on an ongoing basis by women in their childbearing years. They are often more pronounced and irregular adolescence, early twenty-somethings, and perimenopause.

According to the Migraine Research Foundation, “Menstrual migraine is an attack that occurs up to 2 days before and up to 3 days after your period begins. It’s usually more severe and more difficult to treat than other types of migraine. 7-19% of women get menstrual migraine.  About 60% of these women also have migraine at other times of the month, too.”

http://highonclearskin.com/wp-content/uploads/2014/01/cycle.gif

Above, you can see a chart of what is happening with progesterone, estrogen, and testosterone over the course of a standard menstrual cycle.

Notice that around day 27, there is a sharp decline in both progesterone and estrogen. Around this time, testosterone is also at a minimum.

The sharp fall-off of hormones that occurs a few days before menstruation is thought to be the cause of PMS headaches.

Also notice that there is another sharp decline right around ovulation. This time also triggers headaches in some women.

In terms of personal experience, I can say that I do occasionally get headaches around ovulation when my pain issues are exacerbated by other factors.

I also pretty reliably get a spike in pain leading up to menstruation, but I’ve noticed more variance in the number of days. For me, it is usually anywhere from 2-6 days out, but it is occasionally more or less. Sometimes, it simply hits with menstruation.

Usually, if I get the spike a few days out from menstruation, it only lasts for a few hours.

My point in sharing this example is simply that PMS headaches are varied in how they present, and they are not necessarily all migraines either.

2. Estrogen can amp up pain.

Next up, we need to talk about estrogen. Obviously women have more estrogen in their bodies than men during their childbearing years. This too appear to be a factor in pain disorders.

This article on TMJ pain explains:

“It should be noted that articular cartilage is estrogen sensitive. In fibrous joints, such as the temporomandibular joints, estrogen stimulating chemicals have been demonstrated to accelerate DJD and estrogen repressors to slow the process (92). This may partially explain the prevalence of females in most populations of TMD patients. In fact, lower estrogen levels in post menopausal females may partially explain why TMD is less common in the elderly population.”

Also check out this paragraph from Yount:

“One of the most fascinating research findings in recent years is the estrogen receptor on the female’s mast cell. This receptor — genetically coded to provide the female with an inflammation enhancement — is absent in men.”

In other words, the estrogen receptor can amp up inflammation in women. Ouch (literally).

This article adds some further fascinating contributions to our understanding of this issue. As the authors explain:

“Dramatic changes in sex hormones occur around puberty and it is at this point that sex differences in clinical pain conditions also begin to be observed … After the menopause, when levels of estrogen and progesterone are very low, the sex differences in pain become much less marked.”

Additionally, the article describes the results of a study which looked at pain disorders in male-to-female and female-to-male transgender persons undergoing hormone therapy.

The results were astonishing:

“They observed that approximately one third of the MtF subjects developed chronic pain during their treatment with estrogen and androgens, and even those that did not, reported a decreased tolerance to painful events and an enhanced sensitivity to thermal stimuli (both warm and cold). Of those FtM subjects who had chronic pain before the start of treatment, more than half improved after commencing testosterone treatment, reporting reduced numbers of painful episodes and shorter lengths of those that did occur.

So to sum up some of the findings:

  • Tissues which may be associated with pain disorders can be estrogen-sensitive.
  • Inflammation in women is enhanced via the mast cell estrogen receptor.
  • Pain differences between the sexes become pronounced after puberty and reduce after menopause.
  • Transgender persons going from male to female tend to develop chronic pain. Those going from female to male tend to experience pain relief.

These facts when taken into consideration together paint a pretty stark picture of what life is like with lots of estrogen.

http://highonclearskin.com/wp-content/uploads/2014/01/cycle.gif

Above, you can see a chart of what is happening with progesterone, estrogen, and testosterone over the course of a standard menstrual cycle.

Notice that around day 27, there is a sharp decline in both progesterone and estrogen. Around this time, testosterone is also at a minimum.

The sharp fall-off of hormones that occurs a few days before menstruation is thought to be the cause of PMS headaches.

Also notice that there is another sharp decline right around ovulation. This time also triggers headaches in some women.

In terms of personal experience, I can say that I do occasionally get headaches around ovulation when my pain issues are exacerbated by other factors.

I also pretty reliably get a spike in pain leading up to menstruation, but I’ve noticed more variance in the number of days. For me, it is usually anywhere from 2-6 days out, but it is occasionally more or less. Sometimes, it simply hits with menstruation.

Usually, if I get the spike a few days out from menstruation, it only lasts for a few hours.

My point in sharing this example is simply that PMS headaches are varied in how they present, and they are not necessarily all migraines either.

3. Once a month, women’s bodies are flooded with prostaglandins.

As if hormonal fluctuations and estrogen were not enough, women also have to deal with prostaglandins.

Prostaglandins are inflammatory in nature. They are released in large quantities during menstruation in order to stimulate contractions of the uterus in order to shed menstrual blood and tissue.

This not only can lead to painful cramps, but also heightened pain throughout the body.

Trigger points are a poorly understood phenomenon in muscle tissue. Indeed, most of what we have to go on right now is theory rather than fact.

At this point, however, researchers believe that these knots in muscle tissue are points of low circulation, and feature a buildup of inflammatory compounds, among them prostaglandins.

I actually experience the majority of my pain during and after my menstrual period, not before it. To this day, I’m not sure what mechanisms are at work, but prostaglandins do seem like a possible culprit given that trigger points in my neck and shoulders prefer pain to my head.

If you happen to discover that you have trigger points, I highly recommend taking a look at this resource.

You can search by parts of the body or symptoms to try and identify which trigger points might be causing specific patterns of referred pain, including pain in the head or face.

Using that information, you can better target some of your treatments. Quite often, you need to ask you treat the neck, shoulders or back to reduce pain in the head or face.

Back on our main topic, migraines also involve inflammation.

Yount explains:

“When blood levels of neurogenic inflammation chemicals reach a level that the brain perceives as toxic and threatening to brain safety, the migraine receptor is stimulated to cause vasodilation of blood vessels. This serves to flush toxins away from the brain. The pain from a migraine is mostly from the receptors in the blood vessels that are aggravated due to the stretching caused by this sudden enlargement of the blood vessel.”

This is about as clear and straightforward an explanation of migraines as I have ever read. Hopefully it sheds some light for you as well.

While we’re on the subject of inflammation, I will also briefly mention that progesterone has an anti-inflammatory effect on the body.

If (like me) you happen to feel better during the luteal phase of your cycle, the presence of higher amounts of progesterone might help explain that.

4. Testosterone isn’t there to help.

It isn’t just the presence of certain hormones which can heighten pain in females. The lower amounts of at least one hormone is also a contributing factor.

This article explains:

Testosterone appears to have an analgesic effect protecting against the development of painful conditions such as TMJ pain8. Rheumatoid arthritis patients (both male and female) have been shown to have lower androgen levels than sex-matched controls, and androgen administration improves their symptoms, whilst female workers with lower testosterone levels have more work-related neck and shoulder injuries.”

So as a woman, you do not get the painkilling effects of testosterone to nearly the same degree as your male counterparts.

5. Prolactin is another problem.

While estrogen tends to get most of the attention in discussions involving women and pain, prolactin is another possible culprit.

Prolactin is a hormone the female body needs in order to make breast milk.

High production of prolactin is associated with a number of PMS symptoms.

This study reports, ” We recruited 29 patients with microprolactinoma and headache: 16 with migraine (group A) and 13 with tension-type-headache (group B). The prolactin (PRL) levels measured during attacks of headache were significantly higher in nine patients (56%) of group A and in one patient (8%) of group B.”

Both studies which I have linked to above suggest to dopamine agonists as an effective treatment.

One such dopamine agonist which can be particularly successful is Vitex. This is why we have included it as an ingredient in our migraine supplement, My Brain!

I have experienced outstanding results from taking Vitex, and can personally recommend it for headaches which are associated with menstrual issues.

To be clear, as a dopamine agonist, it suppresses prolactin while also promoting progesterone over estrogen.

To go back to what I was saying earlier, progesterone is an anti-inflammatory hormone.

So this may be an additional benefit in suppressing pain. Plus, dopamine itself tends to counteract pain. So by increasing it, you are increasing its analgesic effect.

So by acting on dopamine, prolactin, progesterone and estrogen in favorable ways, Vitex helps combat pain through four different channels.

As a bonus, it is believed that it may have a long-term protective effect against certain forms of cancer.

You can read more about this here.

6. Then there is relaxin to deal with.

By now, we have gone over ample mechanisms to explain why chronic pain tends to be more common and more severe in women than in men.

But we are only about halfway through the list. Next, we will talk about relaxin.

Relaxin is another hormone which fluctuates through your menstrual cycles.

Many people are completely unfamiliar with relaxin. Its role is to loosen up your ligaments in preparation for maturation.

As the BBC reports:

“London’s Portland Hospital surveyed 1,000 osteopaths, and studied 17 women with a regular menstrual cycle.

The study suggests the risk of injury is linked to fluctuating hormone levels which affect the muscles and ligaments.

Both tissues appear to be vulnerable midway through the menstrual cycle, while the ligaments are at greater risk at the end.”

Note that this impact on ligaments can also put joints in danger.

Female athletes have long reported a greater number of injuries close to ovulation or menstruation.

For a long time, this was not well understood. But researchers now are aware that increased levels of relaxin may be causing the joint laxity which leads to these injuries.

If you have issues with joints which are connected to your head pain (i.e. TMD or cervical problems), you should be especially mindful of your joints at these times of the month.

As an example, earlier this year, I was eating lunch when my jaw popped out of place, resulting in a major flare of my myofascial and head pain issues.

It should come as no surprise that this occurred just days before my period.

This is actually how I learned about the hormone relaxin. It was certainly (and remains) a painful lesson.

If you have jaw problems, during times of the month when relaxin is elevated, chew carefully, and avoid opening your mouth wide.

If you have issues with your spine, watch your posture throughout the day, and also through the night.

If you’re going to work out, take extra care, and try not to overextend ligaments or joints.

7. Women often have higher degrees of pain sensitivity and lower degrees of pain tolerance than men.

Now let’s talk about pain sensitivity and pain tolerance. These concepts seem to be defined in varying and sometimes interchangeable ways.

Regardless, there are a couple of components to how we perceive pain:

  • First, there is the physiological pain response to a particular stimulus.
  • Secondly, there is the psychological response to those physiological sensations.

Yount states that, “Further complicating the migraine experience of women is that females exhibit greater sensitivity to laboratory pain as compared to males … Not only are migraines more prevalent in this population but the ensuing pain is felt more intensely.

In clinical experiments which look at pain sensitivity, researchers are able to precisely control the stimulus used to initiate pain responses.

That means that an identical stimulus is used on all participants. Researchers can then measure physiological responses to that stimulus.

An interesting example is discussed in this article. The author references a study which was conducted in 1998 involving the application of heat as a stimulus. The article states explains:

“Not only did the female participants consistently rate the higher 50oC stimulus as more painful than the male participants, but their brains also showed a greater change in activation in response to it, including in the anterior cingulate cortex (a region known to be associated with the evaluation of painful stimuli) and posterior insula (which regulates internal body states).”

The topic is interesting, because there is a widespread cultural perception that women have a lower pain tolerance for men.

But many people fail to realize the same stimulus which produces a lower pain response in a male subject may be assaulting a female subject with much higher levels of physiological pain response.

This is not necessarily to say that the perception is incorrect, but contextually, it is worth taking into account that regardless of their psychological tolerance levels, their higher sensitivity does mean that women on the whole tend to endure more pain than men from an identical stimulus.

Now, just to add to the fun, acute pain can easily develop into chronic pain. This is because the central nervous system begins making unhealthy adaptations in response to pain.

These can be particularly accented in females—more on that in the next section.

There is another article you can read on the development of acute pain into chronic pain in Practical Pain Management.

At this point actually, we may as well press on to the next point, since the next study I wanted to share involves dopamine.

8. Neurotransmitters can get thrown off balance.

There are a few different neurotransmitters which have been connected in one way or another with various chronic pain disorders

Dopamine

This article talks about the relationship between dopamine and chronic pain.

In essence, the dopamine circuit in your brain gets rewired. A. Vania Apkarian, the author of the study referenced in the article, explained, “You can think of chronic pain as the brain getting addicted to pain. The brain circuit that has to do with addiction has gotten involved in the pain process itself.”

This rewiring process reduced available dopamine overall, leading researchers to propose that dopamine agonists such as those used to treat Parkinson’s be considered as a treatment for chronic pain. In animal testing, this produced good results in conjunction with an NSAID.

You probably are aware that dopamine is involved with motivation. This involves not just the motivation to pursue pleasure, but also to escape negative stimuli.

Does this mean that those with the strongest emotional reaction to pain are most likely to develop chronic pain? It would be ironic to say the least.

While this dopamine issue is not necessarily specific to females (I have yet to see statistics on whether it is more prevalent in women or not), it is yet another key factor to consider when evaluating factors which may be contributing to your head pain.

Serotonin

Next up, let’s talk about serotonin. This is another neurotransmitter which modifies the pain response.

Serotonin is particularly linked to fibromyalgia symptoms. Levels of serotonin can vary significantly in fibromyalgia patients, but they are often low.

As a reminder, fibromyalgia is another pain condition which is very much female-oriented.

Treatment with an SSRI or SRNI may produce outstanding results for some fibromyalgia patients.

On this note, it is believed that serotonin may be another pro-inflammatory compound which is present in increased levels in myofascial trigger points.

I do recall seeing a study involving SSRIs as a treatment for patients with arthritis. Unfortunately, I cannot dig up the study, but I do recall the researchers’ conclusion.

It was found that the SSRI used in the study increased arthritic inflammation. So the researchers determined that the SSRI was only a beneficial treatment in patients suffering from arthritis who also have fibromyalgia symptoms driven by low serotonin levels.

I’m actually midway through an experiment on myself involving an SSRI. The jury is still out on whether it might help me. It may be exacerbating my symptoms, but this could be because the dosage is not high enough to act on noradrenalin (see below).

Noradrenalin

Finally, let us discuss noradrenaline, also known as norepinephrine. Yount explains:

“Estrogen and progesterone also induce increased secretions of prostaglandin, which inhibits central norepinephrine release (a nerve messenger in the pain inhibitory system)*, antagonizes morphine analgesia (rendering pain pills not as effective), sensitizes pain receptors (more pain receptors react to same stimulus), and increases neurogenic inflammation.25 This increase in inflammation and pain in the female sets the stage for central nervous system involvement in chronic pain.”

So now you know another problematic effect of prostaglandins.

When they flood your system during menstruation, they not only trigger inflammatory issues in your body, but they also decrease the release of pain-fighting norepinephrine.

*As an aside, it is curious that progesterone can reportedly increase prostaglandins. On the other hand, there seems to be some conflicting data. Take this animal study, which does not seem to find a relationship. Also see this article which reports that EP2 is regulated by estrogen whereas EP1 and EP3 are regulated by progesterone with estradiol. EP2 is particularly implicated in inflammation and vasodilation. As the linked resource states, “An excess of estrogens, deficit of progesterone, or dominance of estrogens can cause increased production of PGE-2 [EP2], resulting in migraine.”)

9. The sympathetic nervous system response may also be aggravated through social factors.

Now we’ve gone over the physiological factors which can contribute to worsening migraines, tension headaches, fibromyalgia and other types of pain in women.

What is easy to overlook is that sociological and environmental factors may also play a role in worsening female pain.

In his article in Practical Pain Management, Yount shares the following:

“The female sympathetic system is enlarged (amygdyla) and more responsive to stimuli. The “lower highway” — the primitive protective system — is enhanced in females that have been subjected to verbal, physical, or sexual abuse. This phenomena is summed up in the term “emotional hijacking” used by Daniel Goleman in his book Emotional Intelligence.”

Obviously these types of abuses are not the sole unfortunate province of women, but in a male-dominated society, it is undeniable that females are more likely to be subject to many of these stressors.

If you read the surrounding context in the article, you can find out more about how the sympathetic nervous system prepares the body for a fight or flight response.

Ideally, this would actually result in fight or flight, but in many modern situations, neither actually occur.

Nonetheless, this has an effect on the entire body, particularly the muscles. Indeed, this has been implicated in the formation of trigger points.

Add to that fact that chronic pain itself is a stressor which can take its toll on the body, and it is easy to see why pain often begets more pain.

10. Society and the medical community have failed to take women’s complaints seriously.

Finally, one more reason why women are more likely to be susceptible than men to chronic pain disorders such as migraines is the fact that the medical system has left them exposed to this threat.

Take a look at this data. As of the time that I’m writing this, here is the breakdown between male and female active physicians:

  • Male: 644,297
  • Female: 345,304

That ratio is clearly very male-dominated.

Of course, things used to be much more skewed. The medical profession for many centuries was almost entirely male (as was the case with most professions).

This being the case, female medical interests were not a high priority.

Indeed, there was a tendency for male physicians for much of history to write off female complaints of pain as hysteria or weakness.

How ironic that these “hysterical females” were quite likely experiencing (and possibly even tolerating) far higher degrees of pain on average than many of the male physicians who were failing to treat them.

Only in relatively recent years has an undercurrent of interest in sex and gender differences regarding pain experiences started to appear.

Sadly, most of the public at large seems to remain largely or entirely ignorant about these differences.

Many people are aware that certain conditions such as migraines are more common in the female population, but do not stop to ask themselves why this might be.

For many researchers and physicians, these conditions continue to remain a low priority.

Cultural perceptions of women as weak or hysterical in the face of pain haven’t really changed all that much either.

Complaints about conditions such as migraines, fibromyalgia and myofascial pain are frequently blown off.

These pains are invisible to the eye, poorly understood, challenging to treat, and rarely improve overnight with a quick fix.

It should come as no surprise that doctors looking for an ego boost rarely want to delve into these types of issues.

Even the existence of some of these conditions is routinely contested both by the general public and the medical community.

But for those who suffer from them, they can be utterly debilitating.

If you have migraines—or any of these other conditions—it is not just in your head. It is in your hormones, your neurotransmitters, your sympathetic nervous system, and often many other aspects of your anatomy.

I would also like to mention that men who suffer from these conditions may sometimes feel even more invisible than women.

After all, while these chronic pain disorders may be female-oriented, none of them are female-exclusive.

Men too can suffer horribly from migraines, myofascial pain, arthritis, and other female-centric conditions.

Society may be even more prone to brushing these male patients off in some respects. After all, a lot of physicians simply may not think for example to consider fibromyalgia as a possible culprit when a male presents with symptoms of that disorder.

Furthermore, men who complain about pain may be perceived as exhibiting “female” traits of hysteria. As a result, they may be urged even more strongly to keep a stoic, stiff upper lip and hide their suffering.

Indeed, hiding suffering is often upheld as “strength” by our culture. It is no wonder that pain disorders go under-diagnosed and pain sufferers are often severely under-treated.

What Can You Do About It?

Whether you are female or male, if you suffer from migraines or have (or suspect you have) another pain disorder which likewise does not receive the attention it deserves, here are some suggestions:

  • Take your health into your own hands. Since your condition may be poorly understood even in the medical community, you will need to be on the cutting edge in terms of investigating your own treatment options. Do not be afraid to depart from the mainstream. Just make sure you are doing your homework.
  • Attempt conservative treatment measures before considering drastic options. Know that many will not produce results overnight, but require time.
  • Advocate for yourself. In many cases, nobody else is going to do it for you. Demand that your headaches or other pain symptoms be taken seriously. If they are not, switch to a provider who is motivated to help you.
  • Do not give up. Even though research in these areas is sorely lacking in many respects, more and more interest is being taken in female-prevalent pain conditions. There have already been breakthroughs in recent years. Do your best to keep up with the research which is unfolding now.
  • Be kind to yourself. All too often, this too is something that only you will be able to do for yourself. Employers, family and even friends may not understand your situation and may make unreasonable demands of you. Respect that your energy and focus may be limited, and remember that stress can make things worse. When you have to, take a break. In other words, set firm boundaries and do not apologize for them.

However many doctors have shrugged off your pain, there is a good chance that your situation can improve once you identify the treatments which are the best fit for you. Do everything you can to give yourself that chance.

More than a few people told me when my headaches started that my situation would never improve, or that I should just “get used to” my suffering.

I decided I deserve better than that—and you do too.

I still struggle with setbacks, but I have made great strides over the years toward reducing pain and enhancing quality of life. Have faith in yourself that you can do the same. You may be surprised at how big a change is possible.

Sources:
https://www.practicalpainmanagement.com/resources/women-chronic-pain
https://www.npr.org/sections/health-shots/2012/04/16/150525391/why-women-suffer-more-migraines-than-men
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677686/
https://health.clevelandclinic.org/women-likely-suffer-chronic-pain/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4589942/
http://www.whiplashandtmj.com/tmdpathomechanics.html
http://www.triggerpoints.net/
https://www.ncbi.nlm.nih.gov/pubmed/18256782
https://www.practicalpainmanagement.com/resources/news-and-research/dopamines-crucial-role-priming-chronic-pain
https://thepsychologist.bps.org.uk/volume-24/edition-6/ouch-different-ways-people-experience-pain
https://www.iflscience.com/brain/parkinsons-drug-could-treat-patients-chronic-pain/
https://rbej.biomedcentral.com/articles/10.1186/1477-7827-10-3
https://www.lifeextension.com/Protocols/Neurological/Migraine/Page-03
https://www.kff.org/other/state-indicator/physicians-by-gender/?currentTimeframe=0&sortModel=%7B%22colId%22:%22Location%22,%22sort%22:%22asc%22%7D