Can I wear tampon all night long?

You can, but you probably shouldn't. You can, but you probably shouldn't. Keeping a tampon in for more than 4-8 hours or so increases the chance that you could get a serious, but very rare, infection called Toxic Shock Syndrome (TSS) that can land you in the hospital. I would try an overnight pad that is designed not to leak. And you shouldn't use a tampon if you're sleeping for more than 8 hours.

Plenty of girls do. Plenty of girls do. The recommended length of time to leave a tampon in is 4-8 hours, though, so if you sleep longer than 8 hours you should use a pad. Personally, I prefer to use a pad and, on some nights, I can even get away with just using a panty liner.

I would have converted back to using pads if I had to wake up at least once in the middle of the night to change my tampon. I love my sleep; it pains me to even get up in the middle of the night to pee. If you’re having a heavier flow, you should probably use a super tampon through the night just to make sure you don’t stain the underwear you’re wearing or worse, your sheets. Just make sure that if you sleep for longer than 8 hours, you set your alarm so you can change your tampon.