Hi, The possible causes of swelling in armpit are: - Infections - bacterial or viral or fungal. Usually these will be associated with pain - Fatty tissue mistaken for swelling - Tissue growths like lipoma, fibroadenoma etc, swelling of lymph nodes - Infection of sweet glands in the armpit - Rarely malignant conditions like breast cancer, lymphoma etc. At your age spotting after one year of menopause with breast pain should be considered as postmenopausal bleeding and has to be evaluated. Hormonal change may be a cause but diagnosis should be made only after thorough examination and investigations. So, please consult your gynecologist once, get examined and go for investigations like Pap smear, ultrasound, sonomammography including the arm pits. With this workup the possible cause of your problem can be identified and treatment can be taken accordingly. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Sree Gouri S. R., OBGYN