The following parameters of blood donors have to be checked prior blood donation:
1. Age - There is a set age before which and after which blood donation can be done or not respectively.
2. Weight - Weight of individuals is also an important factor as underweight individuals are not allowed to donate blood. In underweight individuals, the likelihood of having a reaction such as dizziness and fainting following donation are higher.
3. Heart, lung, and blood disease - Donors are enquired about any prior history of heart, lung, or blood diseases. People with heart disease, heart valve conditions, irregular heartbeat, disease of the blood vessels in the brain, heart failure, and certain lung conditions may be excluded from blood donation. Certain blood diseases such as iron deficiency anemia or leukemia may also lead to exclusion.
4. Other medical conditions - Any other medical condition such as diabetes, hypertension, hypotension, fever etc. are also checked before blood donation.
5. Recent surgery - People with recent surgery are not allowed for donating blood. However, after an year of surgery they can donate blood but only if healing is complete and they have resumed full activity.
6. Pregnancy - Women who are pregnant are not permitted to donate blood during pregnancy and for six weeks after the pregnancy ends.