During the past decade he established a major research programme in the pathogenesis and treatment of cardiovascular disease. He is Joint Editor in Chief of the Journal of the Renin-Angiotensin-Aldosterone System. He has been a member of the editorial boards of several journals, including the Journal of Hypertension, Journal of Human Hypertension and Clinical Science. Professor Sever is a past-president of the British Hypertension Society (1989-1991) and past president of the European Council for Blood Pressure and Cardiovascular Research. He is also a Fellow of the European Society of Cardiology and past Chairman of the Fellowships Committee of the British Heart Foundation. He received the Astra-Zeneca Award from the International Society for Hypertension in 2010 for contributions to the clinical pharmacology of hypertension. In 2011, he gave the Sir George Pickering Lecture to the British Hypertension Society, and was elected as Honorary Fellow of Trinity Hall, Cambridge.
His current research interests in cardiovascular disease include the pathophysiology of vascular disease, the evaluation of anti-hypertensive drug therapy and multiple risk factor intervention in hypertensive populations. He was the Co-Chairman of the Anglo-Scandinavian Cardiac Outcomes Trial, which defined the role of optimal treatment strategies for blood pressure lowering and the role of lipid lowering in the primary prevention of cardiovascular disease in hypertensive patients. He is currently a member of the Executive Committee for the Fourier Trial, one of the first studies investigating the potential benefits of a monoclonal antibody to PCSK9 in the prevention of recurrent cardiovascular events in patients with established cardiovascular disease. He is also interested in the epidemiology of hypertension with particular reference to environmental influences on blood pressure, and ethnic differences.