RT Book, Section
A1 Silverman, Edwin K.
A1 Crapo, James D.
A1 Make, Barry J.
A2 Jameson, J. Larry
A2 Fauci, Anthony S.
A2 Kasper, Dennis L.
A2 Hauser, Stephen L.
A2 Longo, Dan L.
A2 Loscalzo, Joseph
SR Print(0)
ID 1156756504
T1 Chronic Obstructive Pulmonary Disease
T2 Harrison's Principles of Internal Medicine, 20e
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9781259644016
LK accessmedicine.mhmedical.com/content.aspx?aid=1156756504
RD 2024/10/11
AB Chronic  obstructive  pulmonary  disease  (COPD)  is  defined  as  a  disease  state  characterized  by  persistent  respiratory  symptoms  and  airflow  limitation  that  is  not  fully  reversible  (http://www.goldcopd.com/).  COPD  includes  emphysema,  an  anatomically  defined  condition  characterized  by  destruction  of  the  lung  alveoli  with  air  space  enlargement;  chronic  bronchitis,  a  clinically  defined  condition  with  chronic  cough  and  phlegm;  and  small  airway  disease,  a  condition  in  which  small  bronchioles  are  narrowed  and  reduced  in  number.  The  classic  definition  of  COPD  requires  the  presence  of  chronic  airflow  obstruction,  determined  by  spirometry,  that  usually  occurs  in  the  setting  of  noxious  environmental  exposures—most  commonly  cigarette  smoking.  Emphysema,  chronic  bronchitis,  and  small  airway  disease  are  present  in  varying  degrees  in  different  COPD  patients.  Patients  with  a  history  of  cigarette  smoking  without  chronic  airflow  obstruction  may  have  chronic  bronchitis,  emphysema,  and  dyspnea.  Although  these  patients  are  not  included  within  the  classic  definition  of  COPD,  they  may  have  similar  disease  processes.  Respiratory  symptoms  and  other  features  of  COPD  can  occur  in  subjects  who  do  not  meet  a  definition  of  COPD  based  only  on  airflow  obstruction  determined  by  spirometric  thresholds  of  normality.