Just don't do what my dad did.
Spent a year with an issue. Goes to his doctor who gives him pills. Pills barely work so he goes back a year later. Doctor recommends cortisone shot, dad decides on pills for another 6 months. Then finally gets the cortisone shot. Worked for about 3 months. Took him another 6 months to go back. Gets another cortisone shot. Waits again however long, goes for physio. Gets another shot at some point as well.
Probably been about 5 years now and he's still struggling with pain and mobility. For some reason doesn't want to go for a MRI.
It's okay though, because he compensated for pain/mobility for so long now his back is causing him more issues than his shoulder.
I've also tried to get him to go see my doctor, who is younger and goes about things differently than his doctor. But you know, older people are so hard to convince to try new things.