A lip blister (sometimes called a “sucking blister”) is a small bubble, thickened patch, or callus that can form on the upper or lower lip. Many parents are told this means baby has a “strong suck.”Sometimes that’s true. But often, as we discuss - it’s actually a sign that baby is working harder than they need to in order to maintain suction. So rather than being a sign of “strength,” it’s often a sign of compensation. Not every blister means there is tongue restriction — but when paired with other feeding challenges, it can give helpful clues about latch mechanics. What parents may notice: - A small blister, bubble, or white callused area on the upper lip - A thickened strip across the centre of the lip - Lips curling inward during feeds instead of flanging outward - Clicking sounds while feeding - Frequent loss of suction - Milk leaking from the sides of the mouth - Baby tiring quickly or feeding for long periods What it can look like: - A clear fluid-filled bubble that comes and goes - A dry, peeling or thickened patch - A lip that folds under rather than staying relaxed and outward Why this can matter: Feeding should be rhythmic and efficient. If baby cannot maintain a stable seal with the lips and tongue, they may compensate by: - Increasing pressure through the lips - Using more jaw effort - Clamping or sliding on the nipple - Repeatedly breaking and re-establishing suction Over time, this extra friction can create a blister or callus.