- Gongylonemiasis 125.6
- Goniosynechiae 364.73
- Gonococcemia 098.89
- Gonococcus, gonococcal (disease) (infection) (see also condition) 098.0
- Gonocytoma (M9073/1)
- Gonorrhea 098.0
- Good's syndrome 279.06
- Goodpasture's syndrome (pneumorenal) 446.21
- Gopalan's syndrome (burning feet) 266.2
- Gordon's disease (exudative enteropathy) 579.8
- Gorlin-Chaudhry-Moss syndrome 759.89
- Gougerot (-Houwer)-Sjögren syndrome (keratoconjunctivitis sicca) 710.2
- Gougerot's syndrome (trisymptomatic) 709.1
- Gougerot-Blum syndrome (pigmented purpuric lichenoid dermatitis) 709.1
- Gougerot-Carteaud disease or syndrome (confluent reticulate papillomatosis) 701.8
- Gougerot-Hailey-Hailey disease (benign familial chronic pemphigus) 757.39
- Gouley's syndrome (constrictive pericarditis) 423.2
- Goundou 102.6
- Gout, gouty 274.9
- Gowers'
- Gowers-Paton-Kennedy syndrome 377.04
- Gradenigo's syndrome 383.02