#1500    Illness and suffering have always been among the gravest problems confronted in human life. In illness, man experiences his powerlessness, his limitations, and his finitude ( subject to limitations or conditions, as of space, time, circumstances, or the laws of nature). Every illness can make us glimpse death. #1501   Illness can lead to self-absorption, sometimes even to despair and revolt against God. It can also make a person more mature, helping him to discern in his life what is not essential so that he can turn toward that which is. Very often illness provokes a search for God and a return to Him.

#1514   Who should receive this Sacrament?
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."

#1503   Christ's compassion toward all who suffer goes so far that he identifies himself with them: "I was sick and you visited me?" His preferential love for the sick has not ceased through the centuries to draw the very special attention of Christians toward all those who suffer in body and soul. It is the source of tireless efforts to comfort them.

#1505   Moved by so much suffering Christ not only allows himself to be touched by the sick, but he makes their miseries his own: "He took our infirmities and bore our diseases."
Catechism of the Catholic Church.

Extreme Unction as it was called, means the last anointing. This is because it is an anointing with oil. St. James in his Epistle writes of the Anointing of the Sick: "Is any man sick among you? Let him bring in the priests of the church, and let them pray over him, anointing him with oil in the name of the Lord, and the prayer of faith shall save the sick man; and the Lord shall raise him up; and if he be in sins, they shall be forgiven him." (James 5:14-15.) This Sacrament of the Anointing of the Sick gives peace and strength to the soul of the person receiving the Sacrament of the Anointing. "And if he be in sins," says St. James, "they shall be forgiven him." A secondary effect of this Sacrament is to restore bodily health, if God so wills. This effect is often greatly facilitated by the peace of mind which this Sacrament restores to the sick person.

If anyone becomes seriously ill the priest should be notified at once; and the Sacrament of the Anointing of the Sick should be administered, even when danger of death is only remote. It is generally preceded by Confession and Holy Viaticum (Holy Communion). Viaticum means, "food for the journey" the journey into eternity. The Anointing of the Sick be administered, even when the person is unconscious as the result of sickness or accident. In such a case it will remit grave sin, provided the sick person had at least imperfect contrition before becoming unconscious. To receive a Sacrament validly, an adult person must have the intention of receiving the Sacrament. For example, if a person was baptized during his sleep, and had no intention of receiving Baptism, this Baptism would be invalid. All Catholics, unless they have deliberately expressed that they do not wish to receive the Anointing of the Sick, are presumed to have the intention of receiving the Anointing of the Sick; and that presumed intention is sufficient in the case of an unconscious person.
Source: Rev. W. Frean.

Sometimes it is God's goodness that sends sickness, to bring a person back to His worship and the practice of his religion. What does a good father generally do with an unruly child? He advises and warns it, and when words have no effect, punishes it with the rod, not because he wishes to see it suffer, but for its good, that it may give up its evil habits and become an obedient, loving child. In the same way God warns sinners by their conscience, by sermons they hear, by accidents or deaths around them, etc.; and when none of these things have any effect on them, He sends them some affliction - He brings them to a bed of sickness. He punishes them, as it were, with a rod. This He does, not that He may see them suffer, but for their own good; that they may understand He is their Master, the only one who can give them health, that all the doctors and all the friends and money in the world could not save them if He determined that they should die. Then they come to know that the world is not their friend; then they see things as they really are, and begin to think of the next world, of eternity, etc. Thus they again turn to God and to the practices of religion. Many people who reform and begin to lead good lives in sickness would never have changed if God had left them always in good health.

But you must not think that all who are sick are so on account of sin. Sometimes very holy people are in a state of sickness, and then it is sent to them that they may bear it patiently, and have great merit before God for their sufferings, and thus become more holy. Again, very small children who have never sinned are sick, and then it is perhaps that their parents may have merit for patiently taking care of them. As in the case where the husband may have become sick and his wife has to take care of him. Patiently accepting God's will gains many merits. I say that God sometimes sends sickness to people living in sin for the purpose of bringing them back to a better way of living, and in that case their sickness is for them a great mercy from God, who might have allowed them to continue in sin till His judgments and condemnation came suddenly upon them.
Baltimore Catechism No.4.