Before Lourdes built any of its hospitals, it built a system for checking whether the healings people claimed there were real.
What Bernadette reported
In 1858 a fourteen-year-old miller's daughter, Bernadette Soubirous, reported eighteen apparitions of a woman she later identified, under Church questioning, as the Virgin Mary, at a grotto beside the Gave de Pau river. During one apparition she was reportedly directed to a spot where a spring then emerged from previously dry ground, the spring that still supplies the site's baths and fountains.
A bureau built to say no
The Catholic Church established a medical office at Lourdes, now called the Bureau des Constatations Medicales, staffed by physicians, including non-Catholic and non-believing doctors, to examine claimed cures against medical records. The bureau and a further Vatican-level medical committee apply a strict standard: a cure must be sudden, complete, lasting and medically inexplicable given current knowledge. Of many thousands of claimed healings since 1858, the Church has formally recognised only a small number, a low rate that the process itself is designed to produce.
Millions who are not cured
Most of the roughly six million pilgrims Lourdes now receives each year, many of them sick or disabled, do not report a physical cure, and the sanctuary's own literature is explicit that consolation and companionship, not medical results, are the ordinary and expected outcome of the visit.