Infants breathe only through their nose (as they cannot breathe through their mouths for the first 6 months) and will insist on breathing through their nostrils, even though it is blocked. Babies need clear nostrils while feeding, as they have the nipple in their mouth. Thus, a congested nose hampers their feeding patterns, as they won't be able to breathe through their nose. The inability to breathe properly causes irritation to the baby, which in turn concerns and frustrates the mother, thereby, affecting the flow of breast milk. It's a vicious cycle.