結締組織疾病患者若合併有肺臟侵犯，往往導致一定程度的併發症與死亡；而各種結締組織疾病患者或多或少都會波及肺臟、呼吸道或肋膜。乾咳、胸痛或呼吸困難，是最常見的症狀，而間質性肺病為最常見的表現。診斷上需排除感染或藥物相關毒性。肺功能檢查如一氧化碳瀰散試驗或是高解析胸部電腦斷層掃描，可以較早期地偵測肺臟疾病的存在。在放射影像模式和特發性間質性肺炎於病理結果的描述進展，現正應用到結締組織疾病的患者。治療取決於肺部病發症的類型，有些可能追蹤檢查即可；若病程惡化快速，甚至需要投與類固醇或免疫抑制藥物。

Pulmonary involvement in connective tissue diseases (CTDs) often causes significant morbidities and mortalities. During disease course, most patients with connective tissue diseases show signs of involvement of the lung, vasculature, the pleura, and the diaphragm. Pleurisy, coughing, and dyspnea are often the first clues to make the diagnosis. Interstitial lung disease is the most frequent pulmonary manifestation. Differential diagnosis includes respiratory infection and medication-associated lung toxicity. In some asymptomatic patients, abnormal pulmonary function tests (PFTs), including the diffusing capacity for carbon monoxide (DLCO) or abnormal chest high resolution CT (HRCT), may be presented. Descriptions of radiologic patterns and pathologic findings used in the idiopathic interstitial pneumonias are now being applied to patients with CTDs. Corticosteroid or immunosuppressant may be administered based on the disease severity. (J Intern Med Taiwan 2015; 26: 177-185)