I'm going back and forth from Dexilant and Omniprazole due to having Barrett's last year. (no longer have it, but still take medication) I only do Zumba on Wednesday nights, so not a lot of exercise other than walking. My problem is I have very sore armpits and arms both sides. I've had a mammogram this year and everything was fine, however still concerned. What could this be from? Oh...I'm 45 years old as well.