<unk>  occurs most frequently among people older than forty years old. It affects men and women equally. There are no known risk factors; in particular, smoking is not associated with increased risk.
Acute interstitial pneumonitis
Acute eosinophilic pneumonia
Swimming-induced pulmonary edema
Cryptogenic organizing pneumonia
Chemical pneumonitis
Atypical pneumonia
Idiopathic interstitial pneumonia
Malignant pleural effusion