My Mother Is 74 And Is Healthy. Lately She Has

My mother is 74 and is healthy. Lately she has been having a lot of pain in her ribs and her back when she breathes in or out. Can't take deep breaths she has had numerous x rays and they show nothing it really hurts when she burps or breathes. Now her arms hurt. She hasn't done anything for them to hurt. I'm at my wits end. She has been to 5 different doctors in 4 weeks all they have done is take blood, do x- rays and send her home. Last dr did the same but he did a cat scan and haven't heard back. Oh and she has had ekg's at all places 2 times were er visits once by ambulance because she passed out first time for 5 min 2 no time was over 15 min and again took blood x rays and sent her home was there 20 mins