- Idiopathic hypoparathyroidism
- Idiopathic hypogonadotropic hypogonadism
- Hyperuricemia
- Hyperthyroidism
- Hyperosmolar hyperglycemic state
- Hereditary hypomagnesemia
- Hereditary fructose intolerance
- Hepatogenous diabetes
- Hemochromatosis
- Gout
- Goiter
- Gitelman syndrome
- Gestational hyperthyroidism syndrome
- Gaucher disease
- Fulminant type 1 diabetes
- Fibrosing thyroiditis