Breast engorgement occurs when milk production causes swelling and hardness in the breasts. It is usually caused by a delay in breastfeeding after milk comes in around 3-4 days postpartum. Symptoms include pain, swelling, redness, and difficulty latching. Treatment involves frequent breastfeeding or milk expression, applying hot or cold compresses, wearing a supportive bra, and in severe cases medications like pain relievers or drugs to reduce milk production. Preventing engorgement requires initiating breastfeeding early and frequently to empty the breasts regularly.