Cystic nodules in both breasts may or may not be serious, the specific analysis is as follows: 1. Simple breast cysts, cysts caused by milk stagnation at the end of lactation, if the ultrasound shows consistent echogenicity of cystic nodules and there are no obvious symptoms, it is not serious and can be observed regularly and does not require treatment. If it is due to breast duct malformation or nipple malformation during lactation, with breast swelling and pain, accompanied by generalized fever and increased white blood cells, the condition is more serious and requires active treatment to discharge the milk to prevent the formation of pus. 2. Cystic lesions in the breast, due to endocrine disorders, estrogen and progesterone ratio imbalance, resulting in cystic changes in the breast tissue, will appear pain during menstruation, and the pain disappears after menstruation. The pain disappears, and this is not serious. However, if the symptoms persist, there is a risk of malignant transformation, which is very serious.