Toxic shock syndrome is a rare, life-threatening illness triggered by certain bacteria (group A streptococcal and Staphylococcus aureus). In toxic shock syndrome, toxins (poisons) produced by the bacteria cause a severe drop in blood pressure (hypotension) and organ failure. In some patients, these bacteria enter the body through an obvious break in the skin, such as a wound or puncture. Other cases are related to the use of tampons. Sometimes, however, toxic shock develops after a relatively mild injury, such as a bruise or muscle strain, or no cause is identified at all.