Breasts are hard and painful 3 days after giving birth, considering that it may be caused by breast hyperplasia, milk stagnation, acute mastitis, we suggest that patients go to the hospital for examination and diagnosis, and then under the guidance of the doctor for treatment. 1. Mammary gland hyperplasia: due to various reasons, estrogen levels increase, causing patients to develop breast lumps, nodules and other symptoms. 2. Milk stagnation: If the swelling and pain is caused by milk stagnation, it is recommended to massage away the hard lumps in the breasts through breast pump, baby sucking action or manual massage to relieve the discomfort of the breasts. 3. Acute mastitis: The accumulation of milk and bacterial infections can cause acute mastitis, which is a hard and painful condition of the breasts. It is recommended that patients pay attention to rest and avoid exertion. At the same time, the diet should be kept light and easy to digest food, eat more fresh fruits and vegetables, avoid eating spicy stimulating, greasy food.