How is donating blood helpful?
It provides blood for those who lose a lot through surgery, or need it for blood transfusions.
I'm unsure what you're asking. Donating blood won't cause shingles in the person donating blood. If the person donating blood has an active shingles infection they won't allow blood donation at that time. Once the outbreak subsides the blood should be safe to donate. Tell the phlebotomist about the shingles infection, though.
You shouldn't ! As a long-term blood donor (over 35 years) myself, I've never passed out after donating. The amount you donate (500ml) is approximately 10% of your total blood volume - an amount the body can lose without detrimental effect. It's replaced by the body within a few days of donating. Common causes of feinting after giving blood are either (1) they haven't eaten before donating, or (2) haven't rested a short while afterwards…
You will help ensure blood is on the shelf when needed - most people don't ever think they'll need blood, but many do. You will be someones hero - in fact, you may help as many as three people with just one donation. You get a free snack after donating. Further down this page is a link where you can find lots of info about donating blood.
A person has to wait atleast 24 hours after donating blood. I am saying this out of my own experience; I had a beer after i donated blood , and it was i believe 4 hours after the bood donation. I wasn't able to see any thing, it will weeken your eye sight. The worst part is that it will raise your blood pressure to extreme level. the worst thing to do after donating blood…
If the needles are sterilized and the shop/artist doesn't reuse ink, then you can safely donate blood per American Red Cross Guidelines. You should refrain from donating blood for at least one year from the date of the tattoo, if the artist is not following these regulations. The possibility of Hepatitis (and a few other blood borne pathogens) acquired from the tattoo artist's needle would exclude you from donating blood.