First, stay calm. Toxic Shock or TSS is a severe but rare condition that can occur from a bacterial infection. It occurs in about 1 in 100,000 tampon users. TSS can be caused by leaving a tampon in for a long time. This is why it’s very important that you change your tampon every few hours and not leave it in all day or overnight.

Symptoms of TSS:

  • High fever and chills
  • Vomiting
  • Headache
  • Severe muscle aches
  • Diarrhea
  • Feeling extremely weak or dizzy
  • A sunburn-like rash that can get progressively worse as time passes

If you’re using a tampon and experience any of these symptoms, remove the tampon, tell an adult and call your doctor.

TSS has also been associated with menstrual cup use, although very rarely. The numbers are small so it is hard to estimate the actual risk but it is thought to be just as low or even lower than tampon use.