Who is allowed to donate blood? (idea)

In the United Kingdom the following rules apply

People who cannot give blood:

1. You've already given blood in the last 12 weeks (normally, you must wait 16 weeks).
2. You have a chesty cough, sore throat or active cold sore (although the end of a cold is OK).
3. You're currently taking antibiotics or you have just finished a course within the last seven days.
4. You've had hepatitis or jaundice in the last 12 months, likewise any ear or body piercing or tattoos, or you have received a blood transfusion yourself.
5. You've had acupuncture in the last 12 months outside the NHS (unless you can produce the approved certificate from your acupuncturist or physiotherapist).
6. A member of your family (parent, brother, sister or child) has suffered with CJD (Creutzfeld-Jakob Disease).
7. You've ever received human pituitary extract (which was used in some growth hormone or fertility treatments before 1985).

You may not be able to give blood if

1. You've had a serious illness or major surgery in the past or are currently on medication. Please discuss this with the clinical staff. The reason you're taking medicines may prevent you from donating.
2. You've had complicated dental work (although simple fillings are OK on the same day, as are simple extractions after 24 hours).
3. You've been in contact with an infectious disease or have been given certain immunisations in the last four weeks.
4. You're presently on a hospital waiting list or undergoing medical tests.

Also if you are pregnant, have travelled to a malarial zone in the last year, or visited Central or South America ever you cannot donate.

In order to cut back on HIV (although each donation is tested) you should never give blood if

1. You carry the hepatitis B virus, the hepatitis C virus or the HIV virus.
2. You're a man who's had sex with another man, even "safe sex" using a condom.
3. You've ever worked as a prostitute.
4. You've ever injected yourself with drugs - even once.

You should not give blood for 12 months after sex with

1. A man who has had sex with another man (if you're a female).
2. A prostitute.
3. Anyone who has ever injected themselves with drugs.
4. Anyone with haemophilia or a related blood clotting disorder who has received clotting factor concentrates.
5. Anyone of any race who has been sexually active in Africa (apart from Morocco, Algeria, Libya, Tunisia or Egypt) in the past year.

Summarised from http://www.bloodnet.nbs.nhs.uk