[1] He was the younger son of Janet (née Ross) and her husband George Young (1692–1757), an Edinburgh surgeon who later became a physician and is best known for his empiricism and contributions to philosophy.
In this capacity he served at the Battle of Prestonpans where he was taken prisoner after the defeat of the Government Army of General Sir John Cope.
[4] Many of those wounded at the battle were cared for in the newly built Royal Infirmary of Edinburgh and Young, despite his prisoner status, was among the surgeons who treated them.
[5]Young had personal wealth as a result of his family's brewing business[2] and in 1755 he paid for 'fitting up and furnishing' a four bedded lying-in ward in the attic of the Royal Infirmary, the first such facility in Scotland.
[7][5] In 1761 he received the degree of MD from the university for a thesis entitled De Lacte, an analysis of the properties of milk and its use in treatment.
[5] His elder brother George Young had intended to pursue a career in medicine, enrolling at the University of Leiden in 1739.