In addition to fever, mastitis during breastfeeding can be characterized by redness, swelling, pain and localized lumps in the breast skin. These symptoms may be suspicious of mastitis, and a definitive diagnosis requires further examination by a doctor. When there is milk stagnation or cracked nipples, it may cause bacteria to multiply, resulting in inflammation of the mammary gland. The symptoms include localized redness and swelling of the breast, pain, high skin temperature, and even systemic reactions such as chills and high fever. In this case, fever with the above symptoms may be suspected as mastitis. Fever during breastfeeding can also be caused by other reasons, such as common cold, puerperal infection, etc., and requires prompt medical treatment. If you experience any of the above symptoms, it is recommended that you consult a doctor for further examination to determine the cause and treatment. The use of medication should be under the guidance of a doctor.