My baby is suddenly refusing my one side breast.. what will be reason??

A. There is no specific reason as such it’s a very common thing to be seen with kids so I can only suggest if you’re making good amount of feeding I would highly recommend you to express the breastfeed and give it to the medium of a feeding body otherwise the other side will stop making amount of milk that is there and then it should be a problem and the breast size will also be different with passing time