It's not possible for a tampon to get lost inside you. It will stay in your vagina after you've inserted it.
The only other opening is through your cervix at the top of your vagina. However, this is too small for a tampon to pass through.
Tampons have a string at one end that usually stays outside your body. You can remove the tampon at any time using the string. Although it's possible for the string to go inside your body, you'll usually be able to feel the tampon and pull it out.
If a tampon gets stuck inside of you and you can't get it out, go to your GP practice or nearest sexual health clinic. Healthcare staff will be able to remove it for you.
Tampon manufacturers advise that a tampon shouldn’t be left in for more than eight hours. If you can't get to your GP or a sexual health clinic, ring NHS 111 for advice.
Read about what to do if you forget to remove a tampon.
Further information:
Your health, your choices