First, we need to clearly separate long covid from post covid or chronic covid more strictly. In reality, almost nobody is really interested in long covid. If we do so, we see that only 5-10 percent of people are really affected long term.

Second, most of these post covid issues are hard to detect as our medicinal expertise is not advanced enough. There are research groups that try reliable immune marker profiling but this only works for some portion of the post covid group. Other people try specific MRIs or PET scans. In general, if we look long enough, we find damage in any of the post covid patients but that is incredibly costly and not a viable long term strategy. But currently there is no single test (and maybe there never will be) that reliably detects post covid. The issue is that we don’t understand the original damaging process at all and even this process might not be unique. We just see a plethora of different symptoms that we cannot really make sense of.