Physiology or medicine is the third prize category Alfred Nobel mentioned in his will. Nobel had an active interest in medical research. He came into contact with Swedish physiologist Jöns Johansson through Karolinska Institutet around 1890. Johansson worked for a brief period in Nobel's laboratory in Sevran, France during the same year. The Nobel Prize in Physiology or Medicine is awarded by the Nobel Assembly at Karolinska Institutet. This volume is a collection of the Nobel lectures delivered by the Nobel laureates, together with their biographies and the presentation speeches for the period 2016-2020.