- Heyd's syndrome (hepatorenal) 572.4
- HGSIL (high grade squamous intraepithelial lesion) 795.04
- Hibernoma (M8880/0) - see Lipoma
- Hiccough 786.8
- Hiccup (see also Hiccough) 786.8
- Hicks (-Braxton) contractures 644.1
- Hidden penis 752.65
- Hidradenitis (axillaris) (suppurative) 705.83
- Hidradenoma (nodular) (M8400/0) - see also Neoplasm, skin, benign
- Hidrocystoma (M8404/0) - see Neoplasm, skin, benign
- High
- Hildenbrand's disease (typhus) 081.9
- Hilger's syndrome 337.0
- Hill diarrhea 579.1
- Hilliard's lupus (see also Tuberculosis) 017.0
- Hilum - see condition
- Hip - see condition
- Hippel's disease (retinocerebral angiomatosis) 759.6
- Hippus 379.49
- Hirschfeld's disease (acute diabetes mellitus) (see also Diabetes) 250.0
- Hirschsprung's disease or megacolon (congenital) 751.3
- Hirsuties (see also Hypertrichosis) 704.1