Helen Cecily Issler was born in an ambulance on the way to a military hospital in Deolali, near Mumbai, India, her father, a doctor in the British Army, presided over the delivery. Her parents were Polish Jews, her father went to study medicine in Montpellier and then in Geneva. After the outbreak of World War II, the parents fled Europe by ship to India. After India's independence, the family was "repatriated" to Britain, which they had not known before. The father became a general practitioner in Peckham Rye, South London, where Helen grew up and attended the local grammar school. In 1965 she went to study medicine at Lady Margaret Hall in Oxford. At the time, only about one in seven students at the university was female, and only about one in three students came from a state school. She continued her education at the University College Hospital (UCH).