Why do some people experience the same physical injuries/maladies with more physical pain than others? Also, discussion on anxiety, most painful bipolar episodes, and higher prevalence of chronic pain and migraines in people with bipolar disorder.

In my news feed, I saw an interesting article about a woman in the UK who feels almost no pain, despite injuries. In addition, she has felt virtually no anxiety in her life. This has some drawbacks, but identifying why she has virtually no pain and anxiety is obviously useful in science. See At 71, She’s Never Felt Pain or Anxiety. Now Scientists Know Why. - The New York Times

I also decided to look up articles about why some people with equal injuries experience less pain (though still pain) than others with the same injuries. Unlike the woman referenced above, I do feel physical pain when injured, but it has been notable in my life that I'm less prone to physical pain than others and far more tolerant of it. I guess I have to knock on wood about this, but so far so good. I'm not sure my flavor of bipolar disorder has anything to do with this. I am aware that many people with bipolar disorder do have plenty of physical pain, many having conditions like fibromyalgia and migraines more than the general public. I have had a period of migraines, but it seemed odd to me that unlike others with bipolar disorder and migraines, my head pain was far less severe than the nausea it caused. See Brain Structure May Predict Pain Sensitivity and
Chronic Pain and Bipolar Disorders: Diagnosis and Treatment

Throughout my life, I have had a lot of anxiety at times, unlike the British lady in the first article. I have also experienced extreme psychological pain of other sorts, too. I will say that my pure severe depressions in my life don't seem to have been as painful psychologically for me as they are for many others who've had severe depressions (not so much hopelessness or SI, but most other symptoms). My severe mixed episodes, however, have been horrendously torturous at times, psychologically (desperation, panic, frustration, fury, frightening psychosis, etc). They are my most dangerous episodes, by far. Unlike the British lady in the first article, I have experienced lots of adrenaline rushes and elation in my life. Having bipolar disorder, especially full blown manias, obviously intensify those experiences. I also notice that when I'm manic, I am even extra tolerant of pain beyond my usual during stability. I tend to injure myself when manic and manic with mixed features a lot (sometimes accidentally, sometimes in rage/desperation), so this has been tested on a number of occasions.

The second article also discusses how people who experience more pain sensitivity in life seem to have less gray matter in the parts of the brain relating to pain. Perhaps this may not have much or any relationship to bipolar disorder, however, it is also interesting to note that gray matter deficiencies, especially in regions of the brain that control inhibition and emotion, have been noted in some people with bipolar disorder. See Global bipolar disorder study reveals thinning of gray matter in brain regions responsible for inhibition and emotion -- ScienceDaily