Coghlan was born in Redfern, a suburb of Sydney, in 1868, to Irish immigrant parents.[1] Her father, Thomas Coghlan, a plasterer, died when Iza was 13.[2] She received a scholarship to attend Sydney Girls High School when it opened in 1883.[3] She enrolled at the University of Sydney in 1887 and was the sole woman in the year's intake of medical students. In 1897, she graduated with a bachelor of medicine and a master of surgery, making her one of the first female graduates in medicine in the state of New South Wales, along with Grace Boelke.[1][2]
Coghlan established a private practice in Sydney in 1893 and began working as a life insurance medical assessor in 1894. From 1910, she medically examined candidates seeking employment in the federal public service, and from 1915 she worked as a medical officer in the NSW Department of Public Instruction. She was a co-founder and president of the NSW Medical Women's Society and worked with St John Ambulance Australia to give lectures on first aid and home nursing.[1]
She never married, and retired in 1930 to live with two of her sisters in Collaroy in northern Sydney.[1] She died on 1 July 1946 from coronary heart disease.[2] She had eight siblings, including the statistician and engineer Timothy Augustine Coghlan, the lawyer Charles Coghlan, and the politician Cecil Coghlan.[1][4]
