Are blood transfusions permissible in Islam?

a) There is a desperate need to donate blood;

b) There is no other alternative; and

c) This has been prescribed by an expert medical practitioner.

This permissibility is based on the principal of ‘necessity relaxes
prohibition’. (Al-Ashbaah).

However, the permissibility of blood donation and blood transfusion is
determined by the following conditions:

a) The donor willingly donates his blood. If he is compelled to do so,
it will not be permissible;

b) There is no danger to his (the donor’s) life or health;

c) If the doctor feels that the patient will lose his life and there is no
other alternative but recourse of blood transfusion; and

d) There is no fear of death but the recovery is not possible without blood
transfusion.

It is not permissible to sell one’s blood or to pay the blood donor.
However, if one is in need of blood desperately and the only means to obtain
the blood is to purchase it, then only will it be permissible to pay for the
blood.

NB. Blood donation and blood transfusion is not permissible for the sake of
beautification or for any other reason other than genuine necessity.

and Allah Ta’ala Knows Best