PAH or Pah may refer to:

• 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

• 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

• 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)

• Pah Wongso, born Victor Wijnhamer, Jr., (Chinese: 伯王梭; pinyin: Bó Wángsuō), an Indo social worker

• 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

• Pah, the lunar deity in Pawnee mythology
• Pah Wraith, in the fictional Star Trek universe

This disambiguation page lists articles associated with the title PAH.
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