Persons who have a lung transplant need to stay in the intensive care unit (ICU) after their surgery and may remain on the ventilator for a while until their new lung works well enough. A hospital stay is necessary until the transplant team is satisfied with the patient's progress, including making sure there are no signs of rejection. Because the body sees the new lung as "foreign," it makes antibodies to try to reject (destroy) the transplanted lung. For this reason, anyone with a lung transplant must take antirejection medications for the rest of his or her life. In addition to antirejection medications, other treatments continue, including good nutrition, rehabilitation, and supervised exercise programs. Persons who have had a lung transplant should never smoke or be around secondhand smoke. It is crucial for patients to maintain a healthy lifestyle and to follow up as scheduled with the medical team.