Because the conditions of voluntary blood donation are higher than the requirements and standards of blood donation, the results of voluntary blood donation can only prove whether you can participate in voluntary blood donation, and do not have the detailed regulations and requirements of physical examination.
If you donate blood for free, you can only say that your blood meets clinical standards, and it can't prove whether you are healthy or not.
To be precise, it should be said that you can only participate in voluntary blood donation if you are in good health.
Personal suggestions for reference. If you have any questions, ask them.