You have to donate? So donating blood is mandatory where you live? Remarkable...
Well you may feel a bit dizzy after donating, but qfter eating and drinking something you will feel okay. Here I usually get a cup of tea or coffee and sandwich or cake after donating.
I also don't think it hurts you in a magical way. The concept of donating a part of your body is very old and hss persisted in expressions like "give an arm fore someone". Of course it is not literally, but the old intense is as forcefull as the literall expression. Second your donation will help other people. So what you do is a very selfless anf generous act in my eyes, so no, you will not get hurt but dour karma will improve if you do it voluntarily.
Thank you very much
also my mom just think I should donate my blood to hospital to help someone since my king in thailand just pass away last year and he is died in october of last year so most of person said we should do something good for us king so my mom drag me to donate some bloods,well I not mind if I donate some blood for someone else but I not ready yet but it's ended already and thank again for your reply
I doubt it'll affect you much. Blood isn't an exact approximation of life force or every, it just symbolizes that in our workings, so it's not like it'll drain you or anything. On a side note, my local blood bank usually does a whole event during local or regional tragedies. Local businesses donate burgers and stuff, the prisons lend a couple of big barbecue pits, and I think Coca-Cola even dropped off a ton of soda once, and everyone who donates gets a burger and a drink.
Blood is used in many rituals and cultures throughout the world & history. With that being said, some practitioners have used their own blood in their workings or in honor of their deities (i.e. making a promise/bond with them). Donating blood might be a way to honor a deceased king in your culture. I doubt your chakra & magic will change as these things are considered subtle/spiritual. Blood isn't a neccessity in spell work unless you believe it to be. Your blood is physical and your body can replenish the lost blood (if it isn't life threatening).