Literally no downsides. Here’s a non-exhaustive list of a few things you‘ll receive when you donate blood:
– a free checkup
– a blood test for various diseases
– free snacks
– an excuse to take it easy
– the tender realization of how wonderful it is that humans can share blood
– a reminder of your own mortality
– a reminder of the mortality of others
– you get the think about how hard your body must be working to make all this blood
And whole time you’re saving lives too!
