Is it possible for a subject to have a vital capacity with in normal range but a value for fev1 below normal range?

Yes, it is possible for a subject to have a vital capacity within the normal range while having a forced expiratory volume in one second (FEV1) below the normal range. This can occur in conditions like restrictive lung diseases, where lung volumes are reduced but the overall capacity may still appear normal. In such cases, the FEV1 may be affected due to airway obstruction or other factors, indicating a potential issue with airflow despite normal lung capacity.