A tampon is a menstrual product designed to absorb blood and vaginal secretions by insertion into the vagina during menstruation. Unlike a pad, it is placed internally, inside of the vaginal canal. Once inserted correctly, a tampon is held in place by the vagina and expands as it soaks up menstrual blood.
As tampons also absorb the vagina's natural lubrication and bacteria in addition to menstrual blood, they can increase the risk of toxic shock syndrome by changing the normal pH of the vagina and increasing the risk of infections from the bacterium Staphylococcus aureus. TSS is a rare but life-threatening infection that requires immediate medical attention.