Most people can give blood if they are in good health. There are some basic requirements one need to fulfill in order to become a blood donor. Below are some basic eligibility guidelines:

Age:
You are aged between 18 and 65.

Weight:
You weigh at least 50 kg.

Health:
You must be in good health at the time you donate.
You cannot donate if you have a cold, flu, sore throat, cold sore, stomach bug or any other infection.
If you have recently had a tattoo or body piercing you cannot donate for 6 months from the date of the procedure.
You must not donate blood If you do not meet the minimum haemoglobin level for blood donation

You must not give blood:

If you engaged in “at risk” sexual activity in the past 12 months
Individuals with behaviours below will be deferred permanently:
Have ever had a positive test for HIV (AIDS virus)
Have ever injected recreational drugs.

Following pregnancy, the deferral period should last as many months as the duration of the pregnancy.

It is not advisable to donate blood while breast-feeding. Following childbirth, the deferral period is at least 9 months (as for pregnancy) and until 3 months after your baby is significantly weaned (i.e. getting most of his/her nutrition from solids or bottle feeding).