When is it
    permissible to turn off the life support systems of a person who is thought to be dead?
Question

                Many doctors hesitate to decide the
      right time to turn off the life support systems of a person who is clinically dead. The
      doctor has two conflicting feelings: he may think that he is prolonging the agony of the
      dying person, and that if he turns of fthe life support system, he will be giving the
      person the relief of dying. On the other hand, however, he fears that by turning the life
      support systems off, he is depriving the person of the opportunity to continue living.
      When is it permissible to turn off the life support systems in the case of people who are
      clinically dead?
Praise be to Allah.In sharee’ah, a person is considered to be dead and therefore
    subject to all the rulings concerning the deceased, when either of the two following signs
    are noted:
When his heartbeat and breathing stop completely, and the doctors decide
        that they cannot be restarted.

When all the functions of his brain stop completely, and experienced
        doctors and specialists state that this is irreversible, and his brain has started to
        disintegrate.

In these circumstances, it is permissible to turn off life support
    systems, even if some parts of his body – such as the heart, for example – are
    still functioning artificially with the help of these machines.