I m a 51 year old male. I exercise mildly every day, including light weight lifting every other day. About 2 weeks ago, felt a pain in my right arm tricep mainly and secondarily in my bicep and a bit on the front lower right shoulder(not all the time). I stopped lifting. It has decreased much in the past few days, but still lingers a bit. I started using a mouse with my left arm as I thought that may be irritating it as well. This pain happened about a year ago as well and eventually subsided. It feels like probably a pulled muscle, but concern it may have something to do with my heart. It hurts a bit more when I wake up and think maybe I m lying on it wrong. I have had a lot of stress the past couple months, too. Any thoughts? Thanks.