Hello,
Abnormal pain in the armpit is commonly due to
swollen lymph nodes, fatty tissue (lipoma), sore muscles, neuropathy,
breast cancer, etc. You are suggested to get clinically examined by a gynecologist, get mammogram, breast examination, breast USG, breast tissue biopsy,
breast MRI, etc done. If the test shows positive results, get the treatment started at the earliest. If it shows negative reports get treated for the pathology detected.
You should take
vitamin B1, B6, B12 and
analgesic / anti inflammatory medicines for relief. Connect with a physical therapist, do stretch exercises and regular walking. Loose weight if obese. Strain of the muscles and tendons can be treated with massage, pain relieving ointment and rest. Since pain is radiating to the left side you can get a routine cardiac examination and test done to rule out any developing CAD.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Nupur K., General & Family Physician