James Johnston Abraham (he often styled himself J Johnston Abraham)was born in Coleraine, County Londonderry, eldest son of William Abraham JP, a tea merchant originally from County Fermanagh, and Elizabeth Ann Morrison of Toberdoney, County Antrim. He was educated at Coleraine Academical Institution, the University of Dublin where he studied art and medicine, and the London Hospital; his medical qualifications of MB BCh BAO were awarded by Dublin in 1900.

He was house surgeon at the West London Hospital from 1901 until 1906 when he spent a year as ship’s surgeon on SS Clytemnestra (though one researcher disputes this name), after which he was appointed resident medical officer to the London Lock Hospital; he was also assistant surgeon at the Princess Beatrice Hospital and had a general practice in County Clare in southern Ireland. During the First World War he served as medical officer with the Serbian, Egyptian and Portuguese armies, rising to the rank of Lieutenant-Colonel. He coped with inadequate supplies, outbreaks of typhoid, scarlet fever, recurrent fever, smallpox and a typhus epidemic. He was the first doctor on location to diagnose typhus, and he and the Serbian Army Medical Corps managed to contain it. He was a Fellow of the Royal Society of Medicine, President of the Irish Medical Graduates' Association, Chairman of Heinemann’s medical publications, Chairman of the Library Committee of the Athenaeum, and in 1943 was Vicary Lecturer of the Royal College of Surgeons. He was author of A Surgeon's Log (1911), The Night Nurse (1913); A Surgeon's Journal (1957), My Balkan Log (1922) and The Surgeon's Log (1907) which described his year as a ship’s surgeon. In 1937 he published Leaves from a Surgeon’s Case-Book under the nom de plume of James Harpole. 

His various awards and honours included the DSO (1918); CBE (1919); the Serbian Knighthood of St Sava (1915); MD and MA (Dublin 1912); LittD (Dublin,honoris causa, 1946). He married in 1920 (4 April) Lillian Angela Francis of London who survived him by six years.