I've had the pump for over 4 years now. I went through the education on it and everything, and was able to change my infusion sets without incident. I initially put it on my stomach and switched sides every 3 days, but got tired of the fat pockets the pump caused, so I've since moved to my thighs. Anyway, every time I put in a new infusion set now, it itches and hurts within a day. Sometimes I can see redness around the site which is alarming (but my insurance is very anal about how many supplies I get so I sometimes just power through). I want to know why this is happening. It's painful and worrisome. My thighs look scary...I'd honestly post a picture if it wasn't upsetting! Why would it be fine for years? Does the speed of the insulin (like how much a second or whatever) affect this? The only difference is a new device, but the infusion sets have stayed the same. I do have an appointment next week but I'm so frustrated.