The Trøndelag Health Study (The HUNT Study) is a cohort health study performed in the Norwegian county of Trøndelag. HUNT is considered one of the most extensive cohort studies ever conducted in any country. The HUNT Research Centre, which is responsible for collecting and providing access to the data and samples from the study, is part of the Faculty of Medicine and Health Sciences at the Norwegian University of Science and Technology (NTNU). The study was primarily set up to address arterial hypertension, diabetes, screening of tuberculosis, and quality of life. However, the scope has expanded over time. The population based surveys now contribute to important knowledge regarding health related lifestyle, prevalence and incidence of somatic and mental illness and disease, health determinants, and associations between disease phenotypes and genotypes. Participants may be linked in families and followed up longitudinally between the surveys and in several national health- and other registers covering the total population. The HUNT Study includes data from questionnaires, interviews, clinical measurements and biological samples (blood and urine). The questionnaires include questions on socioeconomic conditions, health related behaviours, symptoms, illnesses and diseases. From the beginning, in 1984, every citizen of Nord-Trøndelag being 20 years or older, have been invited to all the surveys for adults, and more than 80% of the population (n=130,000) participated. The population of Nord-Trøndelag was both homogeneous and stable, making it especially suited for epidemiological genetic research. HUNT contains a unique database of personal and family medical histories collected during four surveys (HUNT1, 2, 3 and 4) since 1984. On January 1, 2018, the two counties Sør-Trøndelag and Nord-Trøndelag were merged into one county: Trøndelag, and from the fall of 2019, HUNT was expanded to include the entire county. As of 2017, 170 ph.ds and about 1,700 scientific articles were based on the HUNT material. New articles published in 2017 alone were 110. In 2017 The HUNT Study was awarded the Karl Evang Prize. This Norwegian prize was established in 1981, as a tribute to the former Director of Health, Karl Evang, for his social-medical pioneering efforts. The aim of the award is to stimulate interest and the work for public health and social conditions that have significance for this. (en)