Drnee is, as usually correct and on the money. The problem your older sister has is obesity, and it has progressed to the point where it is life-threatening. She must lose weight. There are surgical protocols available which have minimal complications. One of these involves placing a "band" around the stomach. Have her discuss these options with her physician.
Hi
Welcome to the MedHelp forum!
After reading your post the one thing comes to my mind is TOS or thoracic outlet syndrome which occurs as the result of narrowing of space below and behind the collar bone. Your sister has the classic symptom of the neurogenic variant of TOS characterized by non specific symptoms like pain on raising the arm above the head (as in combing hair, lifting phone to ear), and a tired feeling or numbness in arm. The other possibility is pinched cervical spinal nerves. Vit B12 deficiency is also a possibility. Please consult the trauma specialist or a neurologist regarding this.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!