<prompt> Reduced FEV 1, Normal FVC and FEV 1FVC ratio less than 0.7 .which is reversible with bronchodilator s is consistent withBronchial AsthmaHypersensitivity penumonitisSarcoidosisPolyaeritis nodosa  <response>: In Asthma FEV1forced expiratory volume in 1 second, FVCforced vital capacity, is the total volume exhaled, FEV1FVC decreases. To daignose Asthma: Compatible clinical history plus either : 1FEV112 increase following administration of a bronchodilator or glucocoicoids. 2FEV115 decrease after 6min of exercise 320 diurnal variation on 3days in a weeks on PEFpeak expiratory volume. Reference : Davison, 23rd Edition, page no : 569,555 