What to do if I have a rattle sound in my lungs, is it pneumonia?

Secretions. The rattling sound from lungs is generally due to vibrations produced by retained secretions (mucus/phlegm) in the airways (breathing tubes) in your lungs. Mucus buildup can be due to several reasons - infections, ineffective coughing, bronchitis, chronic smoking, exposure to air pollution etc. Have yr doctor examine you to ensure there are no problems with your lungs that need immediate attention.