PAH or Pah may refer to:
Science and technology Chemistry Polycyclic aromatic hydrocarbon, one of a class of chemical compounds, organic pollutants PAH world hypothesis, hypothesis that proposes that the use of polycyclic aromatic hydrocarbons was a means for the origin of life Polyallylamine hydrochloride, a polyelectrolyte used in polymer sheets Polyanhydrides, a class of biodegradable polymers Photoacid, where H indicates an H atom lost by an acid
Medicine Para-aminohippurate, a substance used in the measurement of blood flow in the kidneys PAH clearance, Para-aminohippuric acid clearance, a measurement of renal plasma flow Paradoxical adipose hyperplasia, a potential complication of cryolipolysis Phenylalanine hydroxylase, an enzyme involved in breaking down phenylalanine Primary alveolar hypoventilation, a condition of inadequate air movement in the lungs Pulmonary arterial hypertension, a condition of elevated blood pressure in the pulmonary artery
Organizations Plataforma de Afectados por la Hipoteca, a Spanish housing rights organization Polish Humanitarian Action, a Polish non-governmental organisation (Polish: Polska Akcja Humanitarna) Russian Academy of Sciences, Russian: Российская Академия Наук (РАН) National Weather Service Paducah, Kentucky (WFO ID PAH)
People Pah Wongso, born Victor Wijnhamer, Jr., (Chinese: 伯王梭; pinyin: Bó Wángsuō), an Indo social worker
Places Pan-American Highway Pah, Gujarat, a village and former non-salute Rajput princely state in Gujarat, India Pah Homestead, a historic home in Hillsborough, Auckland, New Zealand Barkley Regional Airport, Paducah, Kentucky, U.S., IATA airport code PAH Pah-Ute County, Arizona Territory
Other Pah, the lunar deity in Pawnee mythology Pah Wraith, in the fictional Star Trek universe Obsolete spelling of a Māori pā fortification