Breast cancer in pregnancy is usually characterized by breast lumps, bloody nipple discharge, and enlarged lymph nodes in the armpits. However, during pregnancy, the breast is enlarged under the influence of hormones, and it may be accompanied by pain and nipple overflow, etc. Therefore, breast cancer in pregnancy has the characteristic of not being easy to be detected. 1. Breast lumps: Breast lumps are caused by the mutation of breast cells. Breast lumps of breast cancer patients usually have symptoms such as hardness and poor mobility. Usually, breast lumps caused by breast cancer do not cause pain, which is easy to be ignored by patients. 2. Bloody nipple overflow: it usually refers to the bloody nipple overflow caused by breast cancer occurring in the ducts of the breast, and the blood in the ducts follows the ducts to the nipple. 3. Enlarged axillary lymph nodes: Since most of the lymphatic fluid in the breast flows back to the axillary lymph nodes, the symptom of enlarged axillary lymph nodes will appear when the disease progresses to a certain degree. It is recommended that patients go to the hospital in time for diagnosis and treatment under the guidance of the doctor, and do not use medication privately, so as not to cause danger.