Rash?

So this might be tmi idk. But since last night I’ve had a rash it’s kinda like hives. It’s not everywhere on my body but it’s in most places. Mainly on my deck and chest. Should I be concerned? Like should I be worried that’s it’s something serious? At first I thought it could be something I ate but I haven’t really eaten anything and I haven’t eaten anything new. So I don’t think it’s an allergic reaction. I’m thinking it could be stress rash but I’ve never had that before.