This problem of having an "invisible" disease is one that drives me crazy. My mom was a hypochondriac, imagining serious diseases, going for unnecessary tests and complaining constantly for her 87 years, only the last few of which were compromised at all by her health. As a result having quantifiable test results is disproportionately important to me. I did not mention the progressive loss of sensation until it had passed my ankles and I had developed a serious staph infection. I need a demonstrable problem, preferably blood and pus or at least a better than even certainty of something showing up on an MRI or other test to get me into a doctor's office. When I developed Sciatica years go from a ruptured disc I kept going until I couldn't walk.
But I am insane, and this is a bad way to think. Dr. Smith is right. Remember, we wouldn't care so much about what other people think of us if we realized how seldom they do....
But I can sincerely empathize with your desire to have lab certified proof of your disease, beyond your very real suffering and symptoms. I have been known to carry my results with me, although no one, not TSA agents when I need to bring my hiking pole, or attendants at Disney World when I need to take it with in line, have asked to see them! My husband makes fun of me for this need for documentation. He says watching me walk is more than enough proof.
The problem is almost everyone knows someone like my mother, but not everyone knows someone like us.