Breast pain when lifting arms is related to breast trauma, cystic hyperplasia of the breast, acute mastitis and breast cancer. Under normal circumstances, lifting the arm breast will not appear pain, pain should be considered to be caused by breast trauma, in the impact of external forces, the breast area will appear congestion, edema, acute inflammatory changes, at this time will cause breast pain. Excluding traumatic factors, it can be considered a manifestation of cystic hyperplasia, breast hyperplasia is likely to occur in women of childbearing age, when the hormone level continues to increase before menstruation will lead to nodular changes in the breast, the pain before menstruation gradually aggravated, especially when lifting the arms, dressing pain is more obvious. Breastfeeding women due to less attention to local hygiene, nipple area bacterial infection, retrograde up the mammary ducts to form acute mastitis, the local lump will be manifested as redness, swelling, heat and pain will cause difficulty in lifting. Finally, breast cancer can also be considered, the lump will grow faster and metastasize to the axillary lymph nodes during the developmental stage, at this time, there will be axillary lymph node enlargement, pain, and it will also affect the activities of the upper limbs.