PN may refer to:
Pneumonia is an inflammatory condition of the lung affecting primarily the small air sacs known as alveoli.
A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall.
PNC Financial Services Group, Inc. (stylized as PNC) is a bank holding company and financial services corporation based in Pittsburgh.
A pnictogen is one of the chemical elements in group 15 of the periodic table. This group is also known as the nitrogen family.
A pneumatic motor (air motor) or compressed air engine is a type of motor which does mechanical work by expanding compressed air.
Pneumatic tubes (or capsule pipelines; also known as pneumatic tube transport or PTT) are systems that propel cylindrical containers through networks of tubes by compressed air or by partial vacuum.
Pneumococcal vaccines are vaccines against the bacteria Streptococcus pneumoniae. Their use can prevent some cases of pneumonia, meningitis, and sepsis.