IH
- HI (disambiguation)
- Hepatitis A
- Hydrogen iodide
- Icosahedral symmetry
- Idiopathic hypersomnia
- Immune-histochemistry
- Induction heating
- Industrial hygiene
- Információs Hivatal
- International Harvester
- International House World Organisation
- Interstate Highway
- Intracranial hypertension
- List of Latin-script digraphs