Moms who experience medical conditions that cause low milk supply such as previous breast surgery or hypothyroidism can continue to nurse, but make sure their baby receives enough to eat by also supplementing with formula according to Very Well. (romper.com)
Glandular causes for low or no milk production can include previous breast surgery, or hypoplasia / IGT. (kellymom.com)
A woman with previous breast surgery can get mastitis (infection of the breast tissues), galactocele formation (a milk filled tumor in your breast) and even galactorrhea (lactation that occurs without the occurrence of pregnancy or childbirth). (pregnancy-info.net)