Could an ingrown toenail kill you?

Unlikely: But any infection , from any where in the body , if flesh eating bacteria sets in ( necrotizing fascists ) could be lethal if untreated and neglected m more venerable if immunologically compromised ( HIV , chemo , transplant etc ).

I guess this is: What people mean when they say their feet are killing them? In theory, if you ignore an infection and it spreads and you become septic, you can actually die (a lousy way to go), but i've never heard of such a scenario. If you're looking to kill yourself, there are better ways, but speaking to a psychiatrist is your first "step." seriously: don't ignore pain. It's a simple and easy fix.