Pope Francis died of a stroke, causing a coma and "irreversible" heart failure, according to his death certificate released by the Vatican on Monday.
The 88-year-old Catholic leader died on Monday morning, almost a month after having been discharged from five weeks in hospital where he nearly succumbed to double pneumonia.
Francis died at 7.35 am (0535 GMT) in his apartment at the Santa Marta residence in the Vatican. He died of "cerebral stroke, coma, irreversible cardiocirculatory collapse", the death certificate said.
The pontiff had already been affected by a previous episode of acute respiratory failure when he had double pneumonia in hospital, it added.
He had also suffered from arterial hypertension, multiple bronchiectasis and Type 2 diabetes -- something that was not previously known.
It was signed by the director of health of the Vatican City State, professor Andrea Arcangeli.
Agence France-Presse