PDH or PdH may refer to:

• Angiotensin-converting enzyme, an enzyme
• Plesiochronous digital hierarchy, in telecommunications networks
• Pound–Drever–Hall technique for stabilizing a laser's output
• Pyranose dehydrogenase (acceptor), an enzyme
• Pyruvate dehydrogenase, an enzyme
• Party of Humanists (German : Partei der Humanisten), a political party in Germany

This disambiguation page lists articles associated with the title PDH.
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