Over the years this Sacrament has developed and grown in our understanding. Using the Oil of the Infirmed, one of the three Holy Oils consecrated by the Bishop on Holy Thursday, the Sacrament of Healing we call Anointing of the Sick is a healing of mind, body & soul, calling forth the Spirit of God to renew us in our most trying times of physical and emotional turmoil.
Only a Catholic priest is allowed to celebrate the Sacrament of Anointing of the Sick. Because absolution of sins is conferred upon those who are anointed, this Sacrament should be celebrated properly and faithfully, and should never be confused with other prayer oils that may be sold in a religious goods store.
When do I call a priest? The answer to this question is rather simple: when you are extremely sick, before surgery or major medical procedures, upon the diagnosis of an ailment, for the very aged, and in danger of death. Although this Sacrament was once reserved for the time of immediate death, this is no longer the case, and the term "The Last Rites" is no longer in use as part of our Catholic language.
Please do not wait until the last minute to contact a priest. Anointing can be done at anytime for the living, and is reserved only for the living. Priests are not allowed to anoint those who have already died, because all of the Sacraments are for the living.