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Medical terminology is composed of a prefix, root word, and suffix:
Prefix: A prefix is placed at the beginning of a word to modify or change its meaning. Pre means "before." Prefixes may also indicate a location, number, or time.
Root: central part of a word.
Suffix: The ending part of a word that modifies the meaning of the word.
Additional resources:   [Intro to med terms] [Med terms rules] [Med term reference] [Word building reference]  [Practice Exams]

Alphabetical Listing of Med Terms

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Med terms G- med term root list

GlobalRPh Medical Terminology Section- Letter G

Prefixes and Suffixes Medical Terminology beginning with G

Medical terminology is used to precisely describe the human body components, processes, illnesses, medical procedures, and pharmacology. Medical terms are used in the field of medicine, and clinical settings. This section deals with all med terms beginning with the letter G, and features medical roots, prefixes and suffixes. Introduction to Medical Terminology.

Medical Terminology - Letter G 

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ganglion; collection of nerve cell bodies




to freeze, congeal




substance that produces. that which generates


  to produce


producing; forming, generating; formation


produced by or in. pertaining to formation; producing






earth, soil


old age


old age










  gray, silver


glial cells; neuroglial cells, gluey substance


protein, containing protein








glucose; sugar


glucose; sugar


glycogen; animal starch


glucose; sugar




knowledge; to know




sex glands




to go


  record or picture




instrument for recording


writing, record


process of recording




pregnant woman


woman; female


circle, spiral

Med Terms beginning with the letter G

See if you can spot the suffixes, prefixes, and/or root words.


Gait- The way a person walks.

Gallbladder- A pear-shaped sac lodged in a fossa on the visceral surface of the liver, between the right and quadrate liver lobes; functions as a reservoir of bile.

Gallstones- Small, hard stones, usually made of cholesterol or bilirubin, that form in the gallbladder.

Gamete- General term for a mature sperm or ovum. 

Gamma camera- The gamma camera also called the Anger camera and a scintillation camera is the imaging device in nuclear medicine to produce functional scans of the brain, lungs, thyroid, liver, skeleton, gallbladder, and kidneys.

Gamma globulin- A class of serum globulins produced by lymphocytes and plasma cells of the immune system. They exhibit gamma electrophoretic mobility.

Gamma rays- High-energy electromagnetic radiation of the shortest wavelength emitted by an unstable nucleus of an atom produced during radioactive decay.

Ganglion- Benign, fluid-filled tumor masses that usually originate from the joint capsule or tendon sheath.

Ganglionectomy- Surgical removal of a ganglion.

Gangrene- Localized death of body tissue after compromised blood flow (dry gangrene) or bacterial invasion (wet gangrene); usually affects extremities however, it can affect internal organs as well.

Gardnerella vaginalis- Anaerobic gram-variable small coccobacilli responsible for bacterial vaginosis (BV) in women and urethritis in men.



epigastric region
epi- = upon, over
gastr/o = stomach
-ic = pertaining to

Gastrorrhagia - Gastric hemorrhage caused by an injury or infection. 

Gastralgia - Stomach pain.

Gastrectasia - Abdominal dilation.

Gastric analysis- A clinical diagnostic procedure used to examine hydrochloric acid and other stomach secretions. The most common reasons for this test are to look for blood in the gastrointestinal tract or to confirm suspected Zollinger Ellison syndrome.

Gastric antrum- The portion of the stomach adjoining the pylorus, which contains mucus-secreting cells and gastrin-secreting endocrine cells.

Gastric lavage- Emptying the stomach of toxic substances by flushing saline solution, followed by suction of gastric contents.

Gastritis - Inflammation, irritation, or erosion of the gastric mucosa.

Gastrocnemius - The larger, superficial muscle that makes up the calf and contributes to knee flexion.

Gastroenterologist- A doctor who specializes in the study, diagnosis, and treatment of disorders of the digestive system.

gastr/o = stomach
enter/o = small intestine
-logist = one who specializes in the study of

Gastroesophageal reflux disease- backflow of gastric juices from the stomach into the esophagus that is often the result of a weakened cardiac sphincter. It’s also called acid regurgitation or gastroesophageal reflux.

gastr/o = stomach
esophag/o = esophagus
-eal = pertaining to

Gastrointestinal endoscopy- A diagnostic and therapeutic procedure that allows an internist to image, assess, and treat gastrointestinal disorders. It is categorized into i) Upper endoscopy - visualization of organs in the upper GI tract (esophagus, stomach, duodenum, jejunum) and ii) lower endoscopy - visualization of organs in the lower GI tract (rectum, colon, and terminal ileum).

esophagogastroduodenoscopy EGD
esophag/o = esophagus
gastr/o = stomach
duoden/o = duodenum
-scopy = process of viewing

Gastrointestinal (GI) - Collective term for the stomach and intestines.

Gastrointestinal series- A radiographic test used to define the anatomy of the GI tract. An upper GI series reveals structural and functional abnormalities of the upper GI tract whereas a lower GI series is to diagnose problems of the lower GI tract. 

Gastrointestinal tract- Gastrointestinal tract, also called the digestive tract or alimentary canal, a tubular continuum extending from the mouth to the anus. It contains organs of ingestion, digestion, absorption, and excretion.

Gastrorrhagia - Gastric hemorrhage

Gastrospasm - Involuntary contraction of the abdominal muscles, stomach, or intestines.

Gastrotomy- Upper midline or upper left transrectal incision made to examine the interior of the stomach, pylorus, or proximal duodenum. Gastrotomy is performed to control hemorrhage, remove blood clots, benign tumors, and foreign bodies, or insert tubes.

Gavage- Oral dosing. Feeding liquid or semi-liquid foods through a nasogastric tube.

Gonorrhea- A sexually transmitted infection (STI) caused by gram-negative diplococcus Neisseria gonorrhoeae. Though it is referred to as an infection of the genital tract it may also affect skin, eyes, throat, joint, pharynx, or blood.

Gerontological nurse practitioners- Advanced practice registered nurses (APRNs) who specialize in providing care for older patients, usually ages 50 and older.

Granulocyte colony-stimulating factor (G-CSF)- A glycoprotein that facilitates proliferation, differentiation, and survival of neutrophils in the bone marrow.

Gender disorders -Persistent psychological distress that results from the discrepancy between a person's biological sex and their gender identity. 

Gene- Gene, segments of DNA present within chromosomes, carry hereditary information.

Generalized anxiety disorder- An anxiety disorder characterized by chronic, unrealistic apprehension for no specific reason.

Generalized seizure- Generalized seizure affects the whole brain, usually causing loss of consciousness.

Generic name- The chemical name of a drug or a term referring to the 'active ingredient' of a drug. For example, diazepam is the generic name, and Valium or Vazepam is a brand name for the same drug, which is a commonly used anxiolytic.


Genesis- Suffix denoting 'formation', 'beginning', 'origin', or 'generation' as in glycogenesis, the formation of glycogen.

Genital herpes- A sexually transmitted infection (STI)caused by a virus called herpes simplex virus (HSV), characterized by painful blisters and sores on and around the genitals.

Genital warts- Small, raised growths show up on the skin around the genitals and anus.

Genitourinary- A term that refers to the urinary and genital organs. 

Geriatric nurse practitioners- Registered Nurses who provide primary care to aging and elderly individuals.

Geriatricians- Primary care doctors with specialized postgraduate education and experiences in the medical care of older adults

Geriatrics -A specialty focused on diagnosis, treatment, and prevention of disease in elderly individuals. 

German measles- German measles, also called rubella, is a contagious but mild infection caused by the rubella virus; characterized by a red rash that lasts 3 days, hence the name three-day measles.


Denoting old age.

Gerontologist - A gerontology specialist.

Gerontics -Relating to old age or the elderly.

Gerontology - The study of aging from all aspects - biologic, clinical, psychologic, sociologic, legal, economic, and political.

Gerontophobia- An anxiety disorder characterized by an irrational fear of the elderly, of growing old, or both.

Geropsychiatry- A subspecialty of psychiatry dealing with the study, treatment, and prevention of psychiatric aspects of aging and mental disorders in the elderly.

Gestation - The time between conception and birth, during which the fetus develops in the uterus.

Gestational diabetes- A temporary form of diabetes mellitus affecting pregnant women who haven't ever been diagnosed with diabetes; usually dissipates postpartum.

Gestational hypertension- Hypertension develops after 20 weeks of gestation, without proteinuria, and resolves postpartum.

Gestational period- The length of pregnancy, which is calculated as 280 days, or 40 weeks from the first day of the last menstrual period (LMP).

Gigantism- An endocrine disorder characterized by abnormally high linear growth in children; occurs when the pituitary gland makes too much growth hormone.



Denoting gingiva, gums.


Gingivae -Anatomical term for the gums; dense fibrous tissue, covered by a mucosal membrane, that surrounds the teeth and the marginal parts of the alveolar bone.

Gingivitis- Gum inflammation, or red, swollen, and bleeding gums.


Glands- A gland is an organ, cell, or tissue specialized to secrete substances for use in the body. There are many glands throughout the body, but they all fall into two types: endocrine and exocrine.

Glandular tissue- Glandular tissue, or glandular epithelium, forms most of the body's glands. They synthesize, store, and secrete extracellular products (e.g., mucus, enzymes, sweat, sebum, hormones, etc).

Glans penis- Head or tip of the penis.


Denoting gray, silver

Glaucoma- An umbrella term for the ocular diseases caused due to increased intraocular pressure; characterized by atrophy of the optic nerve which creates a gray gleam in the affected eyes.


Denoting glia, glue

Glioblastoma multiforme- Malignant Grade IV brain affecting glial cells; characterized by rapid invasive growth and distinct genetic subtypes, it accounts for 60% of brain tumors in adults.

Glioma- An umbrella term for different types of glial tumors: astrocytoma, oligodendroglioma, and glioblastoma.


Globin-Globin, the protein portion of hemoglobin. Designated as alpha 1 and 2, and beta 1 and 2, globins permit hemoglobin to transport oxygen.

Globulins- A group of serum proteins made in the liver. They are classified as alpha, beta, or gamma depending on their electrophoretic mobility.


Denoting glomerulus

Glomerulonephritis- Acute or chronic inflammation of the glomeruli. 

Glomerulus- A tuft of anastomosing capillaries located in the renal cortex.

Glomerular filtrate- The fluid that filters out the blood through the capillary walls of glomeruli. It has the same composition as plasma but with far less plasma proteins or cells and more water, glucose, amino acids, salts, urea, and creatinine.

Glomerular filtration rate (GFR)- The volume of fluid filtered in the glomerulus per unit of time; considered the best overall index of renal function


- Denoting word, speech, or tongue.

Glossal- Pertaining to the tongue, lingual.

Glossitis - Inflamed or beefy red tongue.

Glottis- The glottis, otherwise known anatomically as the rima glottidis, is the natural space between the vocal folds in the larynx.



- Denoting glucose, sugar.

Glucocorticoids- Steroid hormones produced by the adrenal cortex, and have anti-inflammatory, immunosuppressant, metabolic, and endocrine effects.

Glucagon- A polypeptide hormone secreted by the alpha-cells of the pancreatic islets; by promoting glycogenolysis and gluconeogenesis, glucagon plays a significant role in preventing a fall in blood glucose levels.  

Gluconeogenesis- Synthesis of glucose from non-carbohydrates, especially amino acids and glycerol.

Glucose- The simplest of the carbohydrates; also the cell's primary source of energy.


Gluteus maximus- The largest of the three buttocks muscles, responsible for the movement of hip and thigh.

Gluteus medius- The middle of the three buttocks muscles, responsible for the outwards rotation of the thigh, enables a steady walking gait.


Denoting sugar, glucose, sweetness.

Glycogen- Principal form in which carbohydrate is stored chiefly in the liver as a reserve of glucose for other cells and tissues.

Glycogenesis- Conversion of glucose to glycogen for storage in the liver and muscle cells for later use as needed. It takes place when blood sugar levels are high.

glyc/o = sugar, sweet
-genesis = the production of; formation of

Glycogenolysis- The breakdown of glycogen into glucose when blood glucose levels are low; primarily occurs in the myocytes and hepatocytes.

Glycolysis- Glycolysis, a series of ten enzyme-catalyzed reactions that release energy within glucose; occurs in the cytoplasm of almost all organisms.

Glycosuria- Abnormally high levels of sugars, especially glucose, in the urine.


Combining form denoting diagnosis, or knowledge


Goiter- Hyperplasia or enlargement of the thyroid gland due to iodine deficiency in the diet. Other causes of goiter include hyperthyroidism, inflammation, thyroid cancer, or autoimmune reactions.


Denoting gonads.

Gonadocorticoids- Sex hormones secreted by the inner layer of the adrenal cortex.

Gonadotropic- Denoting the secretions of the anterior pituitary gland.

Gonadotropin- Glycoprotein hormones secreted by the anterior pituitary gland and the placenta, and act on the gonads.

Gonads- A term used to refer to the glands that produce sperm in males and eggs in females.

Gonioscopy- A differential diagnostic procedure for the evaluation of the anterior chamber angle (ACA). It helps to categorize the type of glaucoma i.e., open- or closed-angle.


Goodell’s sign- Softening of the uterine cervix around the sixth week of gestation; a sign of pregnancy.

Gout- A painful form of arthritis, affecting a single joint at a time - usually the big toe but can also affect joints in feet, hands, wrists, elbows, or knees.

Graafian follicle- Fluid-filled spherical cavity for the developing ovum in the cortex of the ovary.

Graft-- A graft is the transplantation of healthy tissue or an organ to repair or rebuild diseased tissue or organ in the same person or a separate individual. For example, coronary artery bypass graft (CABG), uses internal mammary arteries, saphenous vein, and radial arteries as grafts.

Grand mal seizure- A tonic-clonic seizure characterized by total body spasm and a sudden loss of consciousness.




Granulocyte-macrophage colony-stimulating factor (GM-CSF)- A cytokine that acts as a hematopoietic growth factor and immune modulator.

Granulocytes- A subset of white blood cells (leukocytes) characterized by enzyme granules. The three types of granulocytes involved in innate and adaptive immunity: neutrophils, eosinophils, and basophils.

Granulocytosis- An abnormally high count of granulocytes in the blood as a reaction to bacterial infection, sepsis, bone marrow disorders, or use of corticosteroids.


Suffix denoting an instrument for recording, as in radiograph, cardiograph


Refers to writing


Suffix denoting the process of recording, as in radiography, cardiography.


Graves’ disease- Occurs when the immune system makes thyroid-stimulating immunoglobulin (TSI), an antibody that mimics the action of thyroid-stimulating hormone (TSH), causing excessive secretion of thyroxine (T4) and triiodothyronine (T3). Also called toxic diffuse goiter or exophthalmic goiter.


pregnant woman

Gravida- A pregnant woman.

Gray matter- A major part of the central nervous system that is mostly neuronal cell bodies and unmyelinated axons, giving a gray appearance.

Greenstick fracture- Partial fracture; one side of a bone is broken and the other is bent (like a tree's green branch). Mostly occur in infants or toddlers.

Growth hormone (GH)- Growth hormone (GH), also known as somatotropin, a peptide hormone secreted by the anterior pituitary. GH stimulates tissue growth and protein synthesis for tissue repair.

Grunting- The deep, abnormal expiratory sound caused by a sudden closure of the glottis; usually observed in infants suffering from respiratory distress.

Glucose tolerance test- The glucose tolerance test, also known as the oral glucose tolerance test (OGTT), determines the body’s ability to metabolize sugar and how rapidly it gets cleared from the blood. It is performed to diagnose gestational diabetes, as well as diabetes mellitus if glucose levels are in the borderline zone.

Guillain-Barré syndrome-- Guillain–Barre syndrome (GBS), also known as Landry's paralysis1, is an immune-mediated disorder of the peripheral nervous system (PNS). GBS is typically triggered by a respiratory or gastrointestinal infection, or an aberrant autoimmune response targeting peripheral nerves and their spinal roots, leading to loss of reflex and paralysis.

Gums- Gums, also known as the gingiva, pink-colored keratinized mucosa that surrounds and protects the teeth.


woman; female


Gynecologist- A physician who specializes in female reproductive health.

Gynecology -The branch of medicine that deals with the diagnosis, treatment, and care of the female reproductive system.

Alphabetical Listing of Med Terms

a b c d e f g h i j k l m
n o p q r s t u v w x y z



Increasing your understanding of medical terminology

Additional references:

Word Building Reference- This resource strengthens your understanding of medical terminology. See how common medical terms are created using the various prefixes, suffixes, and root words.

Medical Terminology Intuitive Section hot-anim This section was developed for 'speed learning' of medical terminology. Start by reviewing the meanings for a block of medical terms, and then go back and choose a previous term randomly and try to recall the meaning of that particular medical term before hovering over the term to determine the answer. These frequent mini-tests will accelerate the learning process and in a relatively short period of time, you will be able to quickly recall the meaning of all of the listed medical terms. This method of learning is superior to flash cards because of the frequent exposure and testing of your recall.




Med terms G- med term root list