ICD-10-CM
- Gaisböck's disease (polycythemia hypertonica)
- Galactokinase deficiency
- Galactosemia (classic) (congenital)
- Galactosuria
- GALD (gestational alloimmune liver disease)
- Galeazzi's fracture
- Galeophobia
- Gallop rhythm
- Gamna's disease (siderotic splenomegaly)
- Gamophobia
- Gampsodactylia (congenital)
- Gamstorp's disease (adynamia episodica hereditaria)
- Gandy-Nanta disease (siderotic splenomegaly)
- Gangliocytoma
- Ganglioneuromatosis
- Gangosa
- Ganister disease
- Ganser's syndrome (hysterical)
- Gardner-Diamond syndrome (autoerythrocyte sensitization)
- Gargoylism
- Garrod's pad, knuckle
- Gastrodisciasis, gastrodiscoidiasis
- Gastroenteroptosis
- Gastroesophageal laceration- hemorrhage syndrome
- Gastroliths
- Gastromalacia
- Gastroptosis
- Gastroschisis (congenital)
- Gastrostenosis
- Gatophobia
- Gaucher's disease or splenomegaly (adult) (infantile)
- Gee (-Herter)(-Thaysen) disease (nontropical sprue)
- Gemination, tooth, teeth
- Genito-anorectal syndrome
- Geographic tongue
- Gephyrophobia
- Gerbode defect
- GERD (gastroesophageal reflux disease)
- Gerstmann-Sträussler-Scheinker syndrome (GSS)
- Ghon tubercle, primary infection
- Ghoul hand
- Gianotti-Crosti disease
- Giardiasis
- Gibert's disease or pityriasis
- Gierke's disease (glycogenosis I)
- Gilbert's disease or syndrome
- Gilchrist's disease
- Gilford-Hutchinson disease
- Gilles de la Tourette's disease or syndrome (motor-verbal tic)
- Gingivoglossitis
- Glanders
- Glanzmann (-Naegeli) disease or thrombasthenia
- Glazed tongue
- Gleet (gonococcal)
- Glénard's disease
- Gliomatosis cerebri
- Globinuria
- Globus (hystericus)
- Glossagra
- Glossalgia
- Glossocele
- Glossoncus
- Glossopathy
- Glossophytia
- Glossoplegia
- Glossoptosis
- Glossopyrosis
- Glossotrichia
- Glossy skin
- Glucoglycinuria
- Glucose-galactose malabsorption
- GLUT1 deficiency syndrome 1, infantile onset
- GLUT1 deficiency syndrome 2, childhood onset
- Glutaric aciduria
- Glycinemia
- Glycinuria (renal) (with ketosis)
- Glycopenia
- Gnathostoma spinigerum (infection) (infestation), gnathostomiasis (wandering swelling)
- Goiter-deafness syndrome
- Goldberg-Maxwell syndrome
- Goldberg syndrome
- Goldblatt's hypertension or kidney
- Goldenhar (-Gorlin) syndrome
- Goldscheider's disease
- Goldstein's disease (familial hemorrhagic telangiectasia)
- Gongylonemiasis
- Gonococcemia
- Goodall's disease
- Goodpasture's syndrome
- Gopalan's syndrome (burning feet)
- Gorlin-Chaudry-Moss syndrome
- Gottron's papules
- Gougerot's syndrome (trisymptomatic)
- Gougerot-Blum syndrome (pigmented purpuric lichenoid dermatitis)
- Gougerot-Carteaud disease or syndrome (confluent reticulate papillomatosis)
- Gouley's syndrome (constrictive pericarditis)
- Goundou
- Grainhandler's disease or lung
- Grain mite (itch)
- Granite worker's lung
- Granulomatous tissue (abnormal) (excessive)
- Granulosis rubra nasi
- Graphite fibrosis (of lung)
- Grating scapula
- Grawitz tumor
- Gray syndrome (newborn)
- Green sickness
- Greenstick fracture - code as Fracture, by site
- Grey syndrome (newborn)
- Griesinger's disease
- Grinder's lung or pneumoconiosis
- Grisel's disease
- Grooved tongue
- Ground itch
- Grover's disease or syndrome
- Growing pains, children
- Gruby's disease
- Gubler-Millard paralysis or syndrome
- Guerin-Stern syndrome
- Guidance, insufficient anterior (occlusal)
- Guinea worms (infection) (infestation)
- Guinon's disease (motor-verbal tic)
- Gull's disease
- Gunn's syndrome
- Gynandrism
- Gynecomastia
- Gynephobia
- Gyrate scalp