COPD is commonly seen in smokers and presents with an obstructive pattern on pulmonary function tests, which is not seen in this patient.

Though the patient has chest tightness, a key factor for asthma, her lack of other symptoms such as wheezing, allergic rhinitis or a family history makes this less likely.

The patient's history of working in a textile factory, coupled with a restrictive pattern on pulmonary function tests, is indicative of pneumoconiosis, a occupational lung disease caused by the inhalation of dust.

Pleural effusion would present with signs of fluid overload such as jugular venous distention or peripheral edema, which are not seen in this patient.