The appearance of a hard swelling in the breast, like the size of a pea, is relatively common in the clinic, and the reasons for this generally include the following: First, it may be a normal hyperplastic breast nodule, and there are no uncomfortable symptoms, but when touched inadvertently can be touched like a small pea-sized swelling, relatively hard, which are normal benign breast hyperplasia nodules caused. Second, for young women is a benign breast fibroid, this situation is very common in young women around 18-20 years old, excessive proliferation of fibrous tissue gradually formed tumor-like, this situation also belongs to benign tumor. Third, it may also be due to malignant tumors of the breast, including breast cancer, breast sarcoma, which appears as a bean-sized swelling, and hard, and hard texture, and even bad mobility, should go to the hospital early for a detailed examination to find the cause or after the diagnosis, should take the surgical treatment program for complete eradication.