Hi Traci, I just wrote a couple of thoughts on this issue as a post, since my thinking seems to diverge from some other hosts' responses to your questions and in a couple of similar threads. I'll link to that below in case you're curious, but basically, a lot of hosts seem to view stained sheets as your (the Host's) problem. I do not, and as a woman, I'm offended when a woman asks me to understand that she just cost me more than her booking to replace sheets because she forgot her period was coming again like it has every month for years.
In my post I offer super polite sample text that hosts can use to request reimbursement, and we've had most guests reply completely graciously and immediately accept the charges (we buy either Ralph Lauren sheets at Home Goods for $60-$70, or the higher end Target sheets for $40-$50, so we just request that as reimbursement). As info for other hosts, the first time someone left blood stains on our sheets, we were unsure of the expectation on our end, so we called Superhost Support for guidance - the rep seemed **horrified** that we were considering attempting to wash someone else's blood out ourselves. I say this because a lot of hosts seem to think hosts should spend hours attempting to remove blood or other body fluid stains, which seems completely nuts to me (from a time value perspective as well as a health and safety perspective). The person who bled on your sheets may know that they don't have a communicable disease, but the host doesn't.
TLDR: Don't let other hosts make you feel bad for wanting to be reimbursed for something that was ruined (and sheets bled on by a stranger are ruined - most guests don't leave you needing to scrub out their blood). Keep on keepin on! 🙂
https://community.airbnb.com/t5/New-Hosts/Support-for-Hosts-with-Bloody-Sheets/m-p/301507#M25910