<unk> s are commonly caused by accidents in which the skin is pinched by a tool, mechanism, or heavy weight without protective equipment.<unk> s can also arise from forcible human contact, including grappling.<unk> s also may occur with friction caused by constant rubbing of skin against a surface. Ill-fitting shoes that rub on your skin can cause the<unk>  vessels in your skin to break and form a<unk>  clot under your skin, resulting in a<unk> . Certain sports activities that require repeated movement and rubbing of the skin against equipment may also cause this. So baseball pitchers, rowers, and drummers often contract<unk> s on the fingers and palms. They also form as a result of frostbite.<unk> s can also occur in the mouth for a variety of reasons including side effects to certain medications, nutritional deficiencies, and mouth injuries.
Blood blister
Edema blister
Venous hum
Eschar
Aqueous humour
Lesion
Delayed blister
Pus