Chest imaging in asymptomatic smokers aged 50 and under can identify both normal aging changes in the lungs as well as potentially serious conditions. Normal aging changes include bronchial dilation, enlarged alveolar spaces, and pulmonary cysts in over 25% of those over age 75. Potentially serious conditions identified include emphysema, respiratory bronchiolitis, interstitial lung disease such as NSIP and UIP patterns, and air trapping. Screening studies have found that both the prevalence and progression of interstitial lung abnormalities are higher in current smokers. Low-dose CT is now recommended for lung cancer screening in smokers aged 55-74 with at least 30 pack-year history.