rusty colored spit in morning....

[stoop14]

I wake up spit a few times and its rust colored it goes away after a spit a few times or rinse my mouth and is gone all day. I grind my teeth very hard at night could this be the cause?

[Autumn4]

I get exactly the same - sometimes its red blood or brownish. I have some gum inflammation & I grind my teeth. I put so much pressure on that I have cracked 3 teeth in the past. I always worry incase its coming from my throat however I think it must be from gums as its only at night.