The accurate classification of<unk>  is the first step to accurately diagnosing it. in 1998 the American college of chest physicians (CHEST), Expert<unk>  panel postulated that<unk>  should be classified based on its duration. Prior to this, a detailed patient history about the character, timing, sputum production, etc was utilized when evaluating<unk> ; however, the panel found out that these parameters are not sufficient in establishing a definite etiology of<unk> .
The first expert panel in 1998 had initially classified<unk>  as acute<unk> ( ie lasting < 3 weeks) and chronic<unk>  (ie, lasting 3-8 weeks) but  the second American college of chest physicians ACCP panel in 2006 reclassified<unk>  into 3 categories based on its duration as listed below.
Cough classification
Allergy classification
Chest pain classification
Pneumoconiosis classification
Syncope classification
Drug allergy classification
Empyema classification
Atelectasis classification