[ksaun]

Another example of an autoimmune disease that has been becoming more common (not just more frequently diagnosed) is type 1 diabetes (T1D).

(From March, 2020): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146037/

(Increased diagnostic capability seems unlikely to be a factor in T1D's prevalence -- when it is triggered, untreated T1D leads to obvious and serious symptoms (eventually death through ketoacidosis) over the course of months. It's not something you can just ignore and power through; treatment is required to survive.)