I'm trying to come off o2 but when I do my chest feels tight and feels like air isn't going thru why is this I take treatments?

Talk with your. Pulmonary physician for mist accurate explanation.
Depends on disease. A proper answer to this question depends on the reason(s) that you are on oxygen. There are many lung diseases that require oxygen therapy. Some are reversible and improve with therapy and some require long-term chronic oxygen therapy. Diseases that affect other organ systems also may require oxygen therapy.