<s>[INST] Hi, I started with a mild discomfort to my left chest area a few days ago. Now the discomfort is in armpit area to my back left shoulder blade. My armpit is also tender but skin feels numb. I also experienced a period today when my entire arm felt tingly like it had fallen asleep and felt cool to the touch. Any ideas? [/INST] Thanks for posting you query to Chat Doctor .as this type of pain may be due to 1. Muscular causes or 2. Cardiac causes or 3. Neurogenic in origin because of age related degenerative changes leads to compression of nerve. I want to know some more information: is there difficulty in breathing or pain associated with sweating or is it a mild constant pain as these type of feature are usually associated with cardiac pain, and we have to take immediate action .if you are having such symptom immediately consult to cardiac center for father investigation .if such symptom are not you can do following thing :take rest, take hot compression, take pain receiving medicine ; 1. Diclofenac sodium 50 mg two times a day.2. Thiocholchicoside 4 mg two times day for muscle relaxation .hope you would be satisfied with my answer.  Feel free to communicate if any query.regards, Chat Doctor.  </s>