Humanly speaking, Camillus was not a likely candidate for sainthood. His mother died when he was a child, his father neglected him, and he grew up with an excesive love for gambling. At 17 he was afflicted with a disease of his leg that remained with him for life. In Rome, he entered the San Giacomo Hospital for Incurables as both patient and servant, but was dismissed for quarrelsomeness after nine months. He served in the Venetian army for three years. Then in the winter of 1574, when he was 24, he gambled away everything he had–savings, weapons, literally down to his shirt. He accepted work at the Capuchin friary at Manfredonia, and was one day so moved by a sermon of the superior that he began a conversion that changed his whole life. He entered the Capuchin movitiate, but was dismissed because of the apparently incurable sore on his leg. After another stint of service at San Giacomo, he came back to the Capuchins, only to be dismissed again, for the same reason.
Again, back at San Giacomo, his dedication was rewarded by his being made superintendent. He devoted the rest of his life to the care of the sick, and has been named, along with St. John of God, patron of hospitals, nurses and the sick. With the advice of his friend St. Philip Neri, he studied for the priesthood and was ordained at the age of 34. Contrary to the advice of his friend, he left San Giacomo and founded a congregation of his own. As superior, he devoted much of his own time to the care of the sick.
Charity was his first concern, but the physical aspects of the hospital also received his diligent attention. He insisted on cleanliness and the technical competence of those who served the sick. The members of his community bound themselves to serve prisoners and persons infected by the plague as well as those dying in private homes. Some of his men were with troops fighting in Hungary and Croatia in 1595, forming the first recorded military field ambulance. In Naples, he and his men went onto the galleys that had plague and were not allowed to land. He discovered that there were people being buried alive, and ordered his brothers to continue the prayers for the dying 15 minutes after apparent death.
He himself suffered the disease of his leg through his life. In his last illness he left his own bed to see if other patients in the hospital needed help.