Suggest Treatment For Sever Pain In Upper Left Arm

Hi, My mother whom is 78 yrs old has been experiencing EXCRUCIATING pain in her upper left arm. It begins at her elbow and goes to her shoulder...here's the weird thing, when she wakes in the morning she will have a reddish looking bruise, that turns blue as the day goes on. She currently has 4 or 5 bruises and they seem to be radiating toward the inside of her arm. She went to the doctor this morning and they sent her for a ultra sound, to rule out blood clots, which they said looked fine. When I say the pain is bad, it is bad....my mom has a very high tolerance for pain and doesn't complain unless it's really bad. Any suggestions....she is in NC and I am in FL worried sick about her.....thank you!