- Geology: The study of the rocks of a planet.
- Geoponics: It is the study of agriculture.
- Gerontology: Study of the elderly; aging and the special problems of old people.
- Gynecology: It is the study of women’s physiology.
- Heliology: The astronomical study of the sun.
- Hematology: It is the study of the blood, blood forming organs and blood related diseases.
- Hepatology:It is the study of the liver, gallbladder, pancreas and the biliary diseases.
- Histology: The study of the structure of tissues.
- Horticulture: It is the science of cultivating plants for commercial use.
- Hydrodynamics: The mathematical study of the forces, energy and pressure of liquids in motion.