BACKGROUNDThe Global Initiative for Chronic Obstructive Lung Disease (GOLD) recently defined COPD as "A common preventable and treatable disease characterised by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response of the airways and the lung to noxious particles or gases." Though the COPD patients mostly present with the features of acute respiratory infections (productive cough, dyspnoea, etc.), there may be a number of metabolic derangements arising out of the disease process or as a consequence of the therapy instituted like dyselectrolytaemia.This study is aimed at comparing the levels of Sodium, Potassium and Magnesium in Stable COPD and COPD Exacerbation (AECOPD) Patients.