Douglas Jenkinson was brought up on the Wirral peninsula in north-west England and attended Calday Grange Grammar school. He graduated from Liverpool Medical School in 1967. After three years in junior posts in medicine, surgery, pediatrics, and obstetrics and gynecology, he went to Zambia with his family where he spent three years doing general medical duties, obstetrics and gynecology, and neonatal pediatrics. There he discovered his love of research. He returned to the UK in 1973 to join a General Medical Practice partnership in rural Nottinghamshire where, in 1977, he investigated a large outbreak of whooping cough and was the first in 30 years to confirm the benefit of pertussis immunisation. He became a part-time lecturer in General Practice at Nottingham Medical School in 1979, and in 1988 with Professor Idris Williams, set up the first M.Med.Sci. course. He researched and published papers on asthma in addition to whooping cough and sat on the Medical Advisory Committee to the Asthma Society and Friends of the Asthma Research Council. He contributed to textbooks on asthma and child health. He was awarded a doctorate for his whooping cough research in 1996 and continued to research whooping cough after he retired from Keyworth Medical practice in 2011. He has a popular website to help patients with whooping cough get a diagnosis.