In my opinion this transit has nothing to do with physical illnesses,
but rather a harsh ego-death that usually causes depression, anxiety and etc. This transit is one of the best one's to have while going to therapy, because you can work some very dark issues and get something out of it.
The placement of Sun shows where the changes will be felt. In my case, it's the first and second house, so I've been through some major personality-changes a long, long time now.