The sacrament is also called Unction of the Sick, which has exactly the same meaning.
Extreme Unction was the normal name for the sacrament in the West from the late twelfth century until 1972, and was thus used at the Council of Trent and in the 1913 Catholic Encyclopedia. Peter Lombard (d. 1160) is the first writer known to have used the term, which did not become the technical name in the West till towards the end of the twelfth century, and never became current in the East. The word "extreme" (final) indicated either that it was the last of the sacramental unctions or because at that time it was normally administered only when a patient was in extremis
Other names used in the West include the unction or blessing of consecrated oil, the unction of God, and the office of the unction.
In the Greek Church the sacrament is called Euchelaion (Greek Εὐχέλαιον, from εὐχή, "prayer", and ἔλαιον, "oil"). Other names are also used, such as ἅγιον ἔλαιον (holy oil), ἡγιασμένον ἔλαιον (consecrated oil), and χρῖσις or χρῖσμα (anointing).
The Community of Christ uses the term administration to the sick.
The term "last rites" refers to administration to a dying person not only of this sacrament but also of Penance and Holy Communion, the last of which, when administered in such circumstances, is known as "Viaticum", a word whose original meaning in Latin was "provision for the journey". The normal order of administration is: first Penance (if the dying person is physically unable to confess, absolution, conditional on the existence of contrition, is given), then Anointing, then Viaticum (if the person can receive it).
In the Churches mentioned here by name, the oil used (called "oil of the sick" in both West and East) is blessed specifically for this purpose.
Anointing of the Sick is one of the seven Sacraments, and is associated not only with bodily healing but with forgiveness of sins. Only priests can administer it, and "any priest may carry the holy oil with him, so that in a case of necessity he can administer the sacrament of anointing of the sick.
The Catholic Church sees the effects of the sacrament as follows. As the sacrament of Marriage gives grace for the married state, the sacrament of Anointing of the Sick gives grace for the state into which people enter through sickness. Through the sacrament is given a gift of the Holy Spirit that renews confidence and faith in God and strengthens against temptations to discouragement, despair and anguish at the thought of death and the struggle of death; it prevents from losing Christian hope in God's justice, truth and salvation.
The duly blessed oil used in the sacrament is, as laid down in the Apostolic Constitution Sacram unctionem infirmorum, pressed from olives or from other plants. It is blessed by the bishop of the diocese at the Chrism Mass he celebrates on Holy Thursday or on a day close to it. If oil blessed by the bishop is not available, the priest administering the sacrament may bless the oil, but only within the framework of the celebration.
The Roman Rite Anointing of the Sick, as revised in 1972, puts greater stress than in the immediately preceding centuries on the sacrament's aspect of healing, and points to the place sickness holds in the normal life of Christians and its part in the redemptive work of the Church. Canon law permits its administration to any Catholic who has reached the age of reason and is beginning to be put in danger by illness or old age, unless the person in question obstinately persists in a manifestly grave sin. "If there is any doubt as to whether the sick person has reached the use of reason, or is dangerously ill, or is dead, this sacrament is to be administered". There is an obligation to administer it to the sick who, when they were in possession of their faculties, at least implicitly asked for it. A new illness or a renewal or worsening of the first illness enables a person to receive the sacrament a further time.
The sacrament can be administered within Mass, which is the preferred manner. If the celebration takes place outside of Mass, it can be held in the home, in a hospital or institution, or in church. The rite begins with a greeting by the priest, followed by sprinkling of all present with holy water, if deemed desirable, and a short instruction. There follows a penitential act, as at the beginning of Mass. If the sick person wishes to receive the sacrament of penance, it is preferable that the priest make himself available for this during a previous visit; but if the sick person must confess during the celebration of the sacrament of anointing, this confession replaces the penitential rite A passage of Scripture is read, and the priest may give a brief explanation of the reading, a short litany is said, and the priest lays his hands on the head of the sick person and then says a prayer of thanksgiving over the already blessed oil or, if necessary, blesses the oil himself.
The actual anointing of the sick person is done on the forehead, with the prayer "Through this holy anointing may the Lord in his love and mercy help you with the grace of the Holy Spirit", and on the hands, with the prayer "May the Lord who frees you from sin save you and raise you up". To each prayer the sick person, if able, responds: "Amen.
It is permitted, in accordance with local culture and traditions and the condition of the sick person, to anoint other parts of the body in addition, such as the area of pain or injury, but without repeating the sacramental form.
In case of emergency, a single anointing, not necessarily on the forehead, is sufficient.
From the early Middle Ages until after the Second Vatican Council the sacrament was administered, within the Latin Church, only when death was approaching and, in practice, bodily recovery was not ordinarily looked for, giving rise, as mentioned above to the name Extreme Unction (i.e. final anointing). The form used in the Roman Rite included anointing of seven parts of the body while saying (in Latin): "Through this holy unction and His own most tender mercy may the Lord pardon thee whatever sins or faults thou hast committed [quidquid deliquisti] by sight [by hearing, smell, taste, touch, walking, carnal delectation]", the last phrase corresponding to the part of the body that was touched; however, in the words of the 1913 Catholic Encyclopedia, "the unction of the loins is generally, if not universally, omitted in English-speaking countries, and it is of course everywhere forbidden in case of women". Use of this form is still permitted under the conditions mentioned in article 9 of the 2007 motu proprio Summorum Pontificum.
Liturgical rites of the Catholic Church, both Western and Eastern, other than the Roman, have a variety of other forms for celebrating the sacrament.
The solemn form of Eastern Christian anointing requires the ministry of seven priests. A table is prepared, upon which is set a vessel containing wheat. Into the wheat has been placed an empty shrine-lamp, seven candles, and seven anointing brushes. Candles are distributed for all to hold during the service. The rite begins with reading Psalm 50 (the great penitential psalm), followed by the chanting of a special Canon. After this, the senior priest (or bishop) pours pure olive oil and a small amount of wine into the shrine lamp, and says the "Prayer of the Oil", which calls upon God to "...sanctify this Oil, that it may be effectual for those who shall be anointed therewith, unto healing, and unto relief from every passion, every malady of the flesh and of the spirit, and every ill..." Then follow seven series of Epistles, Gospels, long prayers, Ektenias (litanies) and anointings. Each series is served by one of the seven priests in turn. The afflicted one is anointed with the sign of the cross on seven places: the forehead, the nostirls, the cheeks, the lips, the breast, the palms of both hands, and the back of the hands. After the last anointing, the Gospel Book is opened and placed with the writing down upon the head of the one who was anointed, and the senior priest reads the "Prayer of the Gospel". At the end, the anointed kisses the Gospel, the Cross and the right hands of the priests, receiving their blessing.
Anointing is considered to be a public rather than a private sacrament, and so as many of the faithful who are able are encouraged to attend. It should be celebrated in the church when possible, but if this is impossible, it may be served in the home or hospital room of the afflicted.
Anointing may also be given during Forgiveness Vespers and Great Week, on Great and Holy Wednesday, to all who are prepared. Those who receive Unction on Holy Wednesday should go to Holy Communion on Maundy Thursday. The significance of receiving Unction on Holy Wednesday is shored up by the hymns in the Triodion for that day, which speak of the sinful woman who anointed the feet of Christ (). Just as her sins were forgiven because of her penitence, so the faithful are exhorted to repent of their sins. In the same narrative, Jesus says, "in that she hath poured this ointment on my body, she did it for my burial" (Id., v. 12), linking the unction with Christ's death and resurrection.
In some dioceses the Russian Orthodox Church it is customary for the bishop to visit each parish or region of the diocese some time during Great Lent and give Anointing for the faithful, together with the local clergy.
Article 25 of the Thirty-Nine Articles, speaking of the sacraments, says: "Those five commonly called Sacraments, that is to say, Confirmation, Penance, Orders, Matrimony, and extreme Unction, are not to be counted for Sacraments of the Gospel, being such as have grown partly of the corrupt following of the Apostles, partly are states of life allowed in the Scriptures; but yet have not like nature of Sacraments with Baptism, and the Lord's Supper, for that they have not any visible sign or ceremony ordained of God.
Some Anglicans accept that anointing of the sick has a sacramental character and is therefore a channel of God's grace, seeing it as an "outward and visible sign of an inward and spiritual grace" which is the definition of a sacrament.
Liturgical or Mainline Protestant communities (e.g. Presbyterian, Congregationalist/United Church of Christ, Methodist, Lutheran, etc.) all have official yet often optional liturgical rites for the anointing of the sick partly on the model of Western pre-Reformation rites. Anointing need not be associated with grave illness or imminent danger of death.
Protestant communities generally vary widely on the sacramental character of anointing. Non-traditional Protestant communities generally use the term "ordinance" rather than "Sacrament". Mainline Protestants have two sacraments (the Lord's Supper and Baptism), deeming Anointing only a humanly-instituted rite. In Charismatic and Pentecostal communities, anointing of the sick is a frequent practice and has been an important ritual in these communities since the respective movements were founded in the 19th and 20th centuries. These communities use extemporaneous forms of administration at the discretion of the minister, who need not be a pastor. There is minimal ceremony attached to its administration. Usually, several people physically touch (laying on of hands) the recipient during the anointing. It may be part of a worship service with the full assembly of the congregation present, but may also be done in more private settings, such as homes or hospital rooms. Pentecostals (neo-Montanists) believe that physical healing is within the anointing and so there is often great expectation or at least great hope that a miraculous cure or improvement will occur when someone is being prayed over for healing.
In Evangelical and Fundamentalist communities, anointing of the sick is performed with varying degrees of frequency, although laying on of hands may be more common than anointing. The rite would be similar to that of Pentecostals in its simplicity, but would usually not have the same emotionalism attached to it. Unlike Pentecostals, Evangelicals and Fundamentalists generally do not believe that physical healing is within the anointing. Therefore, God may or may not grant physical healing to the sick. The healing conferred by anointing is thus a spiritual event that may not result in physical recovery.
Some Protestant US military chaplains carry the Roman Rite version of the Anointing of the Sick with them for use if called upon to assist wounded or dying soldiers who are Catholics. The Catholic and Orthodox Churches consider invalid as a sacrament the administration of Anointing of the Sick by such chaplains, who in the eyes of those Churches are not validly ordained priests. The rite performed by them is thus seen as having the same by no means negligible value of any other form of prayer offered for the sick or dying.
Administration to the sick is one of the eight sacraments of the Community of Christ. In the Community of Christ the sacrament of administration to the sick has also been known to be used for people seeking spiritual, emotional or mental healing.