Recently I went into a swamp for a few seconds to get out to my canoe which was not close to shore. Once in the canoe I had a blunt trauma wound of 1 which was not there before. I had some other wounds I was treating so I figured I may have just missed it. I went to sleep and when I got back on my wound had grown to blunt trauma 5 and I have been in no combats since then. So far I have had no luck treating it with leaches either. I went and checked it on the default client as well just to make sure it wasn't some kind of display error, but it was still a blunt trauma.
I will update with a new screenshot if it keeps going up. Unfortunately I did not get a screenshot when it was only at 1.
Edit: the blunt trauma went up, I have not left my base at all. Still have not successfully treated it with leaches, also cannot treat it with snake juice.
Edit2: Blunt trauma still rising, still have not left base at all, still cannot treat with leaches.
Edit3: was finally able to treat with leaches (after about 2 hours of trying on and off). Still strange how it was going up though.