Why oxygen supplementation contraindicated with obstructive lung disease?

Not usually: COPD is a problem with the ability of the lungs to expel air, which causes poor oxygenation. People with COPD are often treated with oxygen; however, if supplemental oxygen levels are too high it can cut off a person's ability to trigger their own breathing mechanism. If the disease is severe you actually may not be able to survive without the use of oxygen.