Patients will undergo a general medical evaluation by a pulmonary physician (and consultants as appropriate for other organs). The typical routine medical studies to be carried out may include: chest X-ray (posterior-anterior and lateral), non-contrast high resolution CT scan of the chest, pulmonary function tests, electrocardiogram, echocardiogram, general hematologic studies, general serologic studies, /immunologic studies, biochemical analyses (including carboxyhemoglobin to measure blood carbon monoxide levels in order to accurately evaluate the diffusion capacity in individuals who smoke since smoking increases the blood levels of carbon monoxide), alcohol blood test, urinalysis, urine chemistries (including blood or urine nicotine and cotinine test to evaluate urine for active or passive exposure to nicotine), blood or urine drug screening (to evaluate use of recreational drugs and/or mood altering medications), pregnancy test (if applicable) and HIV serology. Also, a sweat chloride and sweat rate test may be performed by the physician to evaluate participants with a possible diagnosis of cystic fibrosis.