If you sleep on your side without squeezing your breasts during breastfeeding, you won’t be able to block your breasts, but if you sleep on your side and squeeze your breasts for a long time, you may block your breasts. You can sleep on your left side or on your right side during breastfeeding. If you sleep on your side and don’t squeeze your breasts, it won’t cause milk blockage. If you sleep on your side and squeeze your breasts for a long time, it may cause a milk blockage over time, but this is not absolute. There is no great restriction on the sleeping position during breastfeeding, either side-lying position or back-lying position is fine, try not to sleep in prone position, which is good for your health and will not affect your milk. It is only when the milk is thick, the milk ducts are congenitally narrowed, and the milk is stagnant that it is easy to block the milk, and after blocking the milk, the breasts will be swollen and painful, and the milk secretion will be reduced, so if there is any abnormality, you should consult a doctor.