- Hardening
- Hare's syndrome (M8010/3) (carcinoma, pulmonary apex) 162.3
- Harelip (see also Cleft, lip) 749.10
- Harkavy's syndrome 446.0
- Harlequin (fetus) 757.1
- Harley's disease (intermittent hemoglobinuria) 283.2
- Harris'
- Hart's disease or syndrome (pellagra-cerebellar ataxia-renal aminoaciduria) 270.0
- Hartmann's pouch (abnormal sacculation of gallbladder neck) 575.8
- Hartnup disease (pellagra-cerebellar ataxia-renal aminoaciduria) 270.0
- Harvester lung 495.0
- Hashimoto's disease or struma (struma lymphomatosa) 245.2
- Hassall-Henle bodies (corneal warts) 371.41
- Haut mal (see also Epilepsy) 345.1
- Haverhill fever 026.1
- Hawaiian wood rose dependence 304.5
- Hawkins' keloid 701.4
- Hay
- Hayem-Faber syndrome (achlorhydric anemia) 280.9
- Hayem-Widal syndrome (acquired hemolytic jaundice) 283.9
- Haygarth's nodosities 715.04
- Hazard-Crile tumor (M8350/3) 193
