- Zagari's disease (xerostomia) 527.7
- Zahorsky's disease (exanthema subitum) (see also Exanthem subitum) 058.10
- Zellweger syndrome 277.86
- Zenker's diverticulum (esophagus) 530.6
- Ziehen-Oppenheim disease 333.6
- Zieve's syndrome (jaundice, hyperlipemia, and hemolytic anemia) 571.1
- Zika fever 066.3
- Zollinger-Ellison syndrome (gastric hypersecretion with pancreatic islet cell tumor) 251.5
- Zona (see also Herpes, zoster) 053.9
- Zoophilia (erotica) 302.1
- Zoophobia 300.29
- Zoster (herpes) (see also Herpes, zoster) 053.9
- Zuelzer (-Ogden) anemia or syndrome (nutritional megaloblastic anemia) 281.2
- Zygodactyly (see also Syndactylism) 755.10
- Zygomycosis 117.7
- Zymotic - see condition
