The swelling and pain in both breasts may be caused by breast cancer, or it may be caused by physiological reasons, breast hyperplasia, mastitis and so on. Breast cancer patients will have the performance of bilateral breast swelling and pain, in addition, patients usually have breast lumps, nipple flattening, retraction, inversion, breast skin is “orange peel” change, nipple overflow and other symptoms. However, breast swelling and pain can also be caused by physiological reasons, for example, some women will have a feeling of breast swelling before menstruation, which can also cause pain when touched. In addition, diseases such as breast hyperplasia and mastitis can also cause patients to have symptoms of bilateral breast swelling and pain. Therefore, a single symptom does not indicate breast cancer, but needs to be combined with other clinical symptoms and auxiliary examinations to clarify, and it is recommended to consult a doctor in time for professional judgment.