Mastitis is an inflammation of the breast tissue, often caused by an infection. It commonly affects women who are breastfeeding, but it can also occur in non-lactating women and men. Symptoms include swelling, pain, redness, and warmth in the affected area, along with flu-like symptoms such as fever and chills. Treatment typically involves antibiotics to clear the infection and pain relievers to reduce discomfort. In breastfeeding mothers, continuing to nurse or pump can help clear the blockage and promote healing. If left untreated, mastitis can lead to abscess formation, requiring further medical intervention.