Mr Nilssen graduated from the University of Cape Town in 1987. He completed ENT training programmes both in South Africa and Scotland with a special interest in Rhinology. He was appointed as a Consultant ENT Surgeon in Portsmouth in 2000.
Mr Nilssen has a general ENT practice with a special emphasis on medical and surgical conditions of the nose. His practice includes Nasal Plastic and Reconstruction surgery of the nose as well as Endoscopic Sinus Surgery (ESS) and extended applications thereof, including nasal and sinus treatments as well as lacrimal conditions in both adults and children.