Most heel blisters form when your skin rubs against your shoes or socks repeatedly over time. The damaged upper layer of skin shears away from the layers beneath and fluid collects in the space to create a firm bubble under the skin – forming the dreaded blister. They develop very quickly, can take several days to heal, and if they break open, they can become infected, making the pain even worse.
Shoe blisters develop most frequently in the summer because those hot humid days can cause our feet to sweat more than usual. When your feet are sweaty it’s a dangerous combination, ripe for feet friction.
New shoes can also cause blisters if they don’t fit correctly as they’re more likely to pinch your feet in areas like your toes or the heel. This causes friction which can damage the skin and cause blisters.