BACKGROUND: Asthma chornic obstructive pulmonary disorder(COPD) overlap syndrome (ACOS) was formally described by the joint project of global initiative for asthma (GINA) and global Initiative for chronic obstructive lung disease (GOLD) as persistent airflow limitation with several features usually associated with both asthma and COPD. ACOS is identified by the features shared with both asthma and COPD.The underlying cause though remains unknown,hence the project did not offer current formal definition.
CASE: This is a case of a 29-year-old male, asthmatic with an eight-pack year smoking history who presented with chronic obstructive respiratory symptoms with non significant improvement on control of exacerbation despite standard maximal  therapy.Diagnostic tests such as pulmonary function Tests,2D Echo,chest CT scan and even assay for alpha 1 anti trypsin were done to rule out for other disease entities and prognosticate the patient's condition leading to the diagnosis of asthma COPD overlap syndrome (ACOS).
CONCLUSION: ACOS as a disease entity is still under debate and still has no current formal definition due to lack of specific biomarkers and lack of defining characteristics.Despite this,management should not be compromised since these patients often present with higher rates of exacerbations,hospitalization,associated co morbid illness and mortality.Treatment therefore is individualized.