Toxic shock syndrome (TSS) is a disease caused by bacteria. It can be fatal, but it’s very rare. One way you can get toxic shock syndrome is by leaving a tampon in too long. Image: © Love Matters You should change your tampon regularly every three to four hours. You should also use the least absorbent tampons you can – so don’t use a ‘super’ tampon if you’ve only got a light flow. Symptoms of TSSIf you show the following symptoms, it's possible that you are suffering from toxic shock syndrome. Sudden high fever Headache Diarrhoea Aching muscles Faintness and tiredness Passing less urine than normal A rash like sunburn appearing within 24 hours Bloodshot eyes If you’ve had a tampon in for a long time, perhaps because you forgot to change it, and you get any three of these symptoms, call your doctor immediately. Stop using tampons and switch to pads.