It's really only fascinating because doctors use the hammer and nail approach to all ailments. If it's not easy an profitable they are not interested. Psychological issues causing physical pain? Not easy. The studies have been done now, and the proof is out there. I'll summarize.
Due to any host of reasons a person may experience negative emotions and especially anxiety. Fear is a big one here. When you get caught in that loop of "what ifs", and "how am I going to fix this" you are in a cycle that reinforces the pain or ailment. You are telling your subconscious brain that you are not safe constantly. It will give you something else to focus on, which is pain. Dr. John Saarno was the first Dr. to uncover this. It has been improved upon since then, and studies with brain imaging have confirmed this.
I had issues with gastritis and lack of appetite in my 20's. Dr's couldn't help me. I noticed after a few years the issue subsided frequently when stress levels were overall lower. So I figured out stress = digestion issues. Couldn't control stress really well. Low T wasn't helping.
Early 30's I developed tendonosis in my arm. That scared me. It spread to the other arm. I've dealt with this for years. It's less of an issue and practically gone now that I've learned it's all caused due to psychosomatic reasons. When I started to get control of this I was hit with back pain so hard I couldn't stand for 2 weeks. The pain was jumping around. Once I recognized is as psychosomatic and brushed it off it disappeared.
If you have/do suffer with a form of depression and/or anxiety and experience physical pain/discomfort that logically should have healed, you are most likely dealing with psychosematically induced pain. You are NOT the 1 in a million genetic freak that hasn't been discovered. You are probably a really intelligent problem solver, but all that thinking about the problem will cause a reaction from the mind to the body.
Sorry to hijack.