The criteria varies per country but in general, being aged 17 to 65 years, having a weight above 50kg, having a normal ranged blood pressure, being psychological fit and not menstruating or breastfeeding for women.
You must rest properly, drink about 1L of water, avoid smoking, be in good health and tell the health personnel concerned if you were recently admitted in a hospital or on any medications.
Ensure you take a sweet drink and some food, avoid alcohol, avoid any strenuous physical exercise within the next 24 hours following the blood donation and ensure not to drive within the next 6 hours.
In the recruitment process, your hemoglobin will be checked and depending on its value, you will be told if you can donate or not.
We all belong to a particular blood group. Your blood will always be needed by someone else. The concept of “strong blood” is a misconception! The frequency of your blood type varies per country and generally, blood group O and A are more common globally.
Yes! Both men and women can equally donate. It is not gender based.
Usually a pint (450cc) of blood is collected from the 5-6L (5000-6000cc) which the body has.
It helps reduce the iron store and prevent conditions such as hemochromatosis, reduces the cholesterol level which is beneficial in individuals with risk factors and helps regenerate new red blood cells through a negative feedback mechanism.

This depends on the type of blood component needed and the gender. Men are recommended to donate after every 12 weeks and women 16 weeks when it concerns red blood cells. Platelet donation can be every 4 weeks.

The pre-screening procedure can last 15 minutes, the donation procedure about 10 minutes and 30 minutes of observation post-donation.
There are very rare in general but you could feel dizzy, have a headache, vertigo, sweating or feeling cold. You could report any discomfort you feel during the procedure to the health personnel attending to you.
Anyone with severe anemia will require blood as soon as possible. Patients with genetic blood diseases such as sickle cell disease, thalessemia, hemophilia, von willebrand disease. Also, victims of motor vehicle accidents, and diseases like malaria, malnutrition all can lead to severe anemia.