1. A pulmonary diagnostic apparatus, including: a first electronic data storage means, and a plurality of expected values stored in said first data storage means, each expected value representing a predicted normal level for a pulmonary function; a first data input means for entering a plurality of value ranges into said first data storage means, each of said ranges corresponding to and encompassing one of said expected values, said first data input means including user operable range input means for adjustably determining the ranges corresponding to each expected value whereby each said range represents a pulmonary function at a level within a normal range as determined by the user; a second data input means for entering a plurality of boundary values into said first data storage means, said boundary values being arranged in sets of consecutively increasing value, each set corresponding to one of said ranges and determining, with respect to its corresponding range, increasing degrees of departure from said range, said second data input means including user operable boundary input means for adjustably determining said boundary values, thereby to determine the degrees of departure corresponding to each range that represent a pulmonary function at increasingly abnormal levels as determined by the user; a pulmonary function testing means for measuring a plurality of pulmonary functions and providing a plurality of performance values to said first data storage means, each performance value based upon a measured pulmonary function and corresponding to one of said expected values; and a processing means operatively associated with said first data storage means for comparing each of said performance values with its corresponding one of said value ranges and generating a first output indicating whether or not said performance value is within said corresponding range, said processing means further comparing each of said performance values lying outside of its corresponding range with its corresponding one of said sets of boundary values and generating a second output indicating a degree of departure from the corresponding range.