While there is some variation depending on tradition, vampires usually are described as looking like ordinary people but with very pale skin that becomes flushed with the consumption of blood. Sometimes the lips and mouth of a vampire are described as red or bloodstained. This appearance is explained by LiveScience as a normal effect of decomposition.
Vampire myths date back at least to the ancient Greeks, who told tales of the goddess Empusa and the striges, who were birdlike creatures that consumed human blood. These creatures of myth evolved into the Romanian vrikolakas; they were hideous stinking walking corpses that became red and gorged with blood. It was thought people with red hair and gray eyes or who had minor deformities would always become vrikolakas. The African Ashanti had the ansabosam; these scary iron-toothed shapeshifters hunted children.
As vampire myths were incorporated into Western literature and myth, the monster began to take on certain common traits: the pale skin of the dead, fangs that were sometimes not visible, abnormally long canine teeth, and a peculiar beauty or charm. Their cold flesh sometimes had an earthy or faintly putrescent odor. As with the vrikolakas, the sleeping vampire was marked by blood - a mouth stained or filled with blood, for instance. The appearance of the vampire is ever evolving; in more modern works of fiction and film, a vampire's appearance is often marked by nothing more than very pale skin.