The Lord Jesus Christ, physician of our souls and bodies, who forgave the sins of the paralytic and restored him to bodily health, has willed that his Church continue, in the power of the Holy Spirit, his work of healing and salvation, even among her own members. This is the purpose of the two sacraments of healing: the sacrament of Penance and the sacrament of Anointing of the Sick.
Source: Catechism of the Catholic Church (Vatican.va)