Whats a friction blister?

Friction blister: Intense rubbing can cause a blister, as can any friction on the skin if continued long enough. This kind of blister is most common after walking long distances or wearing a poorly-tuned new pair of shoes. Blisters are most common on the hands and feet, as these extremities are susceptible while walking, running, or performing repetitive motions.

Friction blister: A friction blister forms as your skin rubs against some material. The skin may become red and irritated and the layers of the skin begin to separate. Your body, in an effort to reduce the offending friction, produces fluid that fills the area resulting in a blister.