1499 “By the sacred anointing of the sick and the prayer of the priests the whole Church commends those who are ill to the suffering and glorified Lord, that he may raise them up and save them. And indeed she exhorts them to contribute to the good of the People of God by freely uniting themselves to the Passion and death of Christ.”
... 1510 However, the apostolic Church has its own rite for the sick, attested to by St. James: “Is any among you sick? Let him call for the elders [presbyters] of the Church and let them pray over him, anointing him with oil in the name of the Lord; and the prayer of faith will save the sick man, and the Lord will raise him up; and if he has committed sins, he will be forgiven.” Tradition has recognized in this rite one of the seven sacraments.
1511 The Church believes and confesses that among the seven sacraments there is one especially intended to strengthen those who are being tried by illness, the Anointing of the Sick: This sacred anointing of the sick was instituted by Christ our Lord as a true and proper sacrament of the New Testament. It is alluded to indeed by Mark, but is recommended to the faithful and promulgated by James the apostle and brother of the Lord.
1512 From ancient times in the liturgical traditions of both East and West, we have testimonies to the practice of anointings of the sick with blessed oil. Over the centuries the Anointing of the Sick was conferred more and more exclusively on those at the point of death. Because of this it received the name “Extreme Unction.” Notwithstanding this evolution the liturgy has never failed to beg the Lord that the sick person may recover his health if it would be conducive to his salvation.
1513 The Apostolic Constitution Sacram unctionem infirmorum, following upon the Second Vatican Council, established that henceforth, in the Roman Rite, the following be observed: The sacrament of Anointing of the Sick is given to those who are seriously ill by anointing them on the forehead and hands with duly blessed oil—pressed from olives or from other plants—saying, only once: “Through this holy anointing may the Lord in his love and mercy help you with the grace of the Holy Spirit. May the Lord who frees you from sin save you and raise you up.”