The sacrament instituted by Christ and celebrated by the Church to offer the healing grace of God to the infirm and the aged, remit sin and make known the prayerful solicitude of the entire body of Christ for those beset by illness or ailment.
Because it is a sacrament for the living, the Anointing of the Sick is celebrated in various places according to the ritual and the appropriate liturgical directives. For instance, a priest may celebrate the sacrament in a sick person’s home, he may celebrate the sacrament with the sick whom he visits in the hospital and he may anoint infirm and aged Catholics during a Mass of the Anointing of the Sick.
When a priest is called to minister to a Catholic who is dying, he will surely anoint this dying person for the purpose of readying him to meet the glorified Lord. Frequently, an anointing of this kind (near death) is preceded by a sacramental confession and followed by Viaticum, the reception of Holy Communion as spiritual food for the journey to the Lord.