I found a good article by Cleveland Clinic on Connective tissue diseases that you might find of interest. It discusses several disorders, what tests are done and how a diagnosis is made and possible treatments.
https://my.clevelandclinic.org/health/diseases/14803-connective-tissue-diseases
After reading your bio, I see you have Sojourns, which is an auto immune disease. I’ve included our Mayo Clinic link to Sojourns for you. https://www.mayoclinic.org/diseases-conditions/sjogrens-syndrome/doctors-departments/ddc-20353223
Many connective tissue diseases are also in this category. Are you concerned what you’re experiencing is more than Sojourns?