The decisive factor proclaiming death is the lifelessness of the area of brain known as the brain stem, which is responsible for vital body functions. Any other vital organ or function, such as the heart or respiration, may temporarily stop, but as long as the brain stem is alive, the said organ or function might be revived. The lives of a number of patients are saved this way. However, when the brain stem itself has died, there is no hope of saving the patient. Based on medical opinion, Muslim jurists are inclined to the view that when brain stem death is ascertained, the human being is dead and certain rulings of the dead are applicable. When brain stem death is certified by a committee of medical specialists, it is lawful to switch off life support systems.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: The definition of death as determined by those who are specialized in Islamic jurisprudence is complete brain death. Prior to that the patient is considered alive and the essentials of life, including water and food, should be supplied.
Having said this, I must say that in Islam, while we encourage treatment and medication as best as we can, we are not encouraged to simply cling to life and keep a person alive on artificial support if there is no hope or improvement in his or her health condition. The person has every right in Islam to refuse treatment and medication if he or she is conscious and sound-minded and feels there is no further benefit in treatment [and doctors confirm this].
Moreover, the prominent Muslim scholar Sheikh Muhammad Iqbal Nadvi, director and imam of Al-Falah Islamic Center, Oakville, Ontario, Canada, states: Death, as determined by the International Council of Muslim Doctors, is only determined by complete brain death. As for heart cessation, it is not an exact definition of death. So, only in the case of brain death can we switch off the life support. But in no case is it allowed to resort to euthanasia to terminate the life of someone.