I took their meaning to be that people with undiagnosed health issues which might be hard to diagnose/understand/treat are frequently dismissed as hypochondriac

I took their meaning to be that people with undiagnosed health issues which might be hard to diagnose/understand/treat are frequently dismissed as hypochondriacs. The implication being that it’s the assignment of “hypochondriac” by lay people distant from the actual medical situation is the ignorant jump to conclusions, not the people seeking medical attention despite being ignored and dismissed.