"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 proper time for receiving this holy anointing has certainly arrived when the believer begins to be in danger of death because of illness or old age. However, each time a Christian falls seriously ill, he may receive the Anointing of the Sick, and also when, after he has received it, the illness worsens.
Only priests can give the sacrament of the Anointing of the Sick, using oil blessed by the bishop.The celebration of the Anointing of the Sick consists essentially in the anointing of the forehead and hands of the sick person (in the Roman Rite) or of other parts of the body (in the Eastern rite), the anointing being accompanied by the liturgical prayer of the celebrant asking for the special grace of this sacrament.