John E. Sarno, a doctor at New York University whose controversial books on the psychological origins of chronic pain sold over a million copies, even while he was largely ignored or maligned by many of his medical peers, died Thursday in Danbury, Conn. He was 93.

His death, at a hospital, was confirmed by his daughter Christina Horner, who said the cause was cardiac failure. He had a home in nearby Carmel, N.Y., as well as one in Manhattan.

He died a day before his 94th birthday and the release of “All the Rage (Saved by Sarno),” a documentary film about him.

Revered by some as a saint and dismissed by others as a quack, Dr. Sarno maintained that most nontraumatic instances of chronic pain — including back pain, gastrointestinal disorders, headaches and fibromyalgia — are physical manifestations of deep-seated psychological anxieties.