“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.”
“The special grace of the sacrament of the Anointing of the Sick has as its effects: the uniting of the sick person to the passion of Christ, for his own good and that of the whole Church; the strengthening, peace, and courage to endure in a Christian manner the sufferings of illness or old age; the forgiveness of sins, if the sick person was not able to obtain it through the sacrament of penance; the restoration of health, if it is conducive to the salvation of his soul; the preparation for passing over to eternal life” (CCC 1532).
Does a person have to be dying to receive this sacrament? No. The Catechism says, “The anointing of the sick is not a sacrament for those only who are at the point of death. Hence, as soon as anyone of the faithful begins to be in danger of death from sickness or old age, the fitting time for him to receive this sacrament has certainly already arrived” (CCC 1514).