To sign blood, first, sign red, then make a sign with both open 5 hands, as if a lot of a liquid is dripping down from a wall. Hold your non-dominant '5' hand up horizontally, palm facing you, then hold your dominant '5' hand vertically in front of the other hand and move it down, as if water was splashed onto a wall and is now dripping down.
Teach your child the blood sign when visiting the doctor for a blood extraction or some lab testing. You can also teach this sign if your inquisitive toddler asks about some blood seen during a minor accident (a small cut or scrape), or when you go to the meat and poultry section of the supermarket.
This is a useful flash card taught best in conjunction with the other medical flash cards. It can also be useful when your toddler shows curiosity about your meat, poultry, or fish preparations in the kitchen.