Bryndís has been a productive scientist and her research has first and foremost focused on sleep and sleep diseases, but also on the effects of heredity and environment on health. A large part of these projects has been carried out in international collaboration, particularly with researchers in the Nordic Countries and at Penn University, Philadelphia, USA. She has served as researcher and project manager in multinational research projects: BOLD, SAGIC, RHINE, RHINESSA and ECRHS. The results of her research have been published in respected international peer-reviewed medical journals, in addition to appearing in the Icelandic Medical Journal. She has held numerous lectures and has published posters at international and domestic conferences.