Early-stage breast cancer almost has no symptoms, and over 90% of breast cancer cases do not involve pain symptoms, especially in the early stages. This means that only early-stage breast cancer combined with breast hyperplasia-like diseases might involve pain. Generally speaking, early-stage breast cancer has no pain symptoms, and one might not feel anything abnormal. It is only during a health checkup that breast cancer can be detected by a breast specialist through palpation or imaging techniques such as color Doppler ultrasound or mammography without the patient feeling any symptoms. Pain may occur only if there is early-stage breast cancer combined with hyperplasia, or if the breast has been injured.