['We have previously described that fraction of exhaled nitric oxide (Feno) levels and blood eosinophil counts offer additive information in relation to asthma and asthma exacerbations when analyzing data from a large population study.', 'We sought to investigate increased Feno levels and blood eosinophil counts in relation to lung function, bronchial hyperresponsiveness (BHR), and asthma control in a cohort of young asthmatic patients.', 'Measurements of Feno levels and blood eosinophil counts were available in 406 subjects (208 women) aged 10 to 35\xa0years. Asthma control was assessed through the Asthma Control Test. Moderate-to-severe BHR was defined as a cumulative dose of methacholine of less than 0.3 mg causing an FEV', 'Subjects with simultaneously increased Feno levels (≥20-25\xa0ppb) and blood eosinophil counts (≥0.3\xa0×\xa010'] Does simultaneously increased fraction of exhaled nitric oxide levels and blood eosinophil count relate to increased asthma morbidity?