Anointing of the Sick
When the Sacrament of Anointing of the Sick is given, the hoped-for effect is that, if it be God's will, the person be physically healed of illness. But even if there is no physical healing, the primary effect of the Sacrament is a spiritual healing by which the sick person receives the Holy Spirit's gift of peace and courage to deal with the difficulties that accompany serious illness or the frailty of old age.
~from the United States Catholic Catechism
"Is anyone among you sick? Let him call for the elders of the church, and let them pray over him, anointing him with oil in the name of the Lord."
Anointing of the sick takes place upon request.