My left wrist is swollen and the finger and thumb hurts. I use the solo loop band, the xl version. I am guessing it is because the watch is too tight, so I am trying it on the right arm for a while. Doesn't feel comfortable, but giving it a try. When I was interested on blood oxygen on my watch 9 before the software issues , It was not tight enough to get it to work. I am hoping down the road, if the app comes back, it can work on a lose band. I , have diabetes type 2 and anemia, the blood oxygen is important to see if the iron is working. The diabetes, I have a cgm so I am fine. But the swollen wrist is going to be an issue.