Provided herein are methods for preventing or treating bronchopulmonary dysplasia (BPD) in a subject. The methods comprise identifying connective tissue mast cells (CTMCs) in a subject and administering an agent that blocks an activity of, blocks an increase in a level of, or reduces a level of the CTMCs in the subject. Also provided are methods of identifying a subject with or at risk for developing BPD. Also provided are methods for determining the effectiveness of a treatment regime for BPD in a subject.