His father was professor in surgery and general practitioner at the National Hospital (Rikshospitalet).

Heiberg was Professor of Pathological Anatomy at the University of Christiania (now University of Oslo) and from 1859 worked was an assistant to Emanuel Winge (1827–90) at the National Hospital as a pathologist and bacteriologist researcher.

[2] He received a one-year scholarship and took a study trip to Würzburg and Vienna in 1869-70.

He was also a general practitioner at the National Hospital, and a specialist in forensic medicine.

He was decorated Knight, First Class of the Royal Norwegian Order of St. Olav in 1890 and was awarded an honorary doctorate at Lund University in 1893.