1.2 Medical Terminology: Prefixes, Roots, and Suffixes
Key Takeaways
- Medical terms are built from three components: prefix (beginning modifier), root/combining form (core meaning), and suffix (ending modifier)
- The combining vowel (usually "o") connects a root to a suffix that begins with a consonant but is dropped when the suffix begins with a vowel
- Common prefixes include hyper- (excessive), hypo- (deficient/below), tachy- (fast), brady- (slow), poly- (many), and dys- (difficult/painful)
- Common suffixes include -itis (inflammation), -ectomy (surgical removal), -osis (abnormal condition), -scopy (visual examination), and -pathy (disease)
- Root words identify the body part or system: cardi/o (heart), hepat/o (liver), nephr/o (kidney), gastr/o (stomach), neur/o (nerve)
- Understanding the word-building system allows CMAAs to interpret unfamiliar medical terms encountered in scheduling, documentation, and patient communication
Last updated: March 2026
Medical Terminology: Prefixes, Roots, and Suffixes
Medical terminology is a standardized language used across healthcare. Rather than memorizing thousands of individual terms, you can learn to decode any medical term by understanding its building blocks.
The Three Components of Medical Terms
Every medical term is built from one or more of these components:
| Component | Position | Function | Example |
|---|---|---|---|
| Prefix | Beginning | Modifies or qualifies the meaning | hypertension (excessive pressure) |
| Root / Combining Form | Middle | Identifies the body part, organ, or system | hypertension (pressure/tension) |
| Suffix | End | Indicates a condition, procedure, or description | hypertension (state/condition) |
The Combining Vowel Rule
A combining vowel (almost always "o") is added between a root and a suffix to make pronunciation easier:
- Use the combining vowel when the suffix begins with a consonant: gastr/o + -scope = gastroscope
- Drop the combining vowel when the suffix begins with a vowel: gastr + -itis = gastritis (not gastroitis)
- Always use the combining vowel between two roots: gastr/o + enter/o + -logy = gastroenterology
Essential Prefixes for CMAAs
Prefixes Indicating Size, Quantity, or Degree
| Prefix | Meaning | Example Term | Definition |
|---|---|---|---|
| hyper- | Excessive, above normal | Hypertension | Abnormally high blood pressure |
| hypo- | Deficient, below normal | Hypoglycemia | Abnormally low blood sugar |
| macro- | Large | Macrocyte | Abnormally large red blood cell |
| micro- | Small | Microscope | Instrument to view small objects |
| poly- | Many, much | Polyuria | Excessive urination |
| oligo- | Few, scanty | Oliguria | Decreased urine output |
| mega-/megalo- | Enlarged | Megalocardia | Enlarged heart |
Prefixes Indicating Time or Speed
| Prefix | Meaning | Example Term | Definition |
|---|---|---|---|
| tachy- | Fast, rapid | Tachycardia | Rapid heart rate (>100 bpm) |
| brady- | Slow | Bradycardia | Slow heart rate (<60 bpm) |
| ante- | Before | Antepartum | Before childbirth |
| post- | After | Postoperative | After surgery |
| pre- | Before | Prenatal | Before birth |
| neo- | New | Neonatal | Pertaining to a newborn |
Prefixes Indicating Location or Direction
| Prefix | Meaning | Example Term | Definition |
|---|---|---|---|
| ab- | Away from | Abduction | Movement away from midline |
| ad- | Toward | Adduction | Movement toward midline |
| endo- | Within, inside | Endoscopy | Visual examination inside a body cavity |
| epi- | Upon, above | Epidermis | Outer layer of skin |
| sub- | Below, under | Subcutaneous | Under the skin |
| peri- | Around | Pericardium | Membrane around the heart |
| inter- | Between | Intercostal | Between the ribs |
| intra- | Within | Intravenous | Within a vein |
| retro- | Behind, backward | Retroperitoneal | Behind the peritoneum |
Prefixes Indicating Negation or Quality
| Prefix | Meaning | Example Term | Definition |
|---|---|---|---|
| a-/an- | Without, absence of | Apnea / Anemia | Without breathing / Without enough blood |
| anti- | Against | Antibiotic | Agent against bacterial infection |
| dys- | Difficult, painful, abnormal | Dyspnea | Difficult breathing |
| eu- | Normal, good | Eupnea | Normal breathing |
| mal- | Bad, poor | Malnutrition | Poor nutrition |
Essential Root Words (Combining Forms)
Body Systems and Organs
| Root/Combining Form | Meaning | Example Term |
|---|---|---|
| cardi/o | Heart | Cardiology (study of the heart) |
| pulmon/o | Lung | Pulmonology (study of the lungs) |
| hepat/o | Liver | Hepatitis (inflammation of the liver) |
| nephr/o, ren/o | Kidney | Nephrology, Renal (pertaining to kidney) |
| gastr/o | Stomach | Gastritis (inflammation of the stomach) |
| enter/o | Intestine | Enteritis (inflammation of the intestine) |
| neur/o | Nerve | Neurology (study of the nervous system) |
| oste/o | Bone | Osteoporosis (porous bones) |
| arthr/o | Joint | Arthritis (inflammation of a joint) |
| dermat/o, derm/o | Skin | Dermatology (study of the skin) |
| hem/o, hemat/o | Blood | Hematology (study of blood) |
| my/o | Muscle | Myalgia (muscle pain) |
| cyt/o | Cell | Cytology (study of cells) |
| path/o | Disease | Pathology (study of disease) |
| cerebr/o | Brain (cerebrum) | Cerebrovascular (pertaining to brain blood vessels) |
| ophthalm/o | Eye | Ophthalmology (study of the eye) |
| ot/o | Ear | Otitis (inflammation of the ear) |
| rhin/o | Nose | Rhinitis (inflammation of the nose) |
| pneum/o | Lung, air | Pneumonia (infection of the lung) |
| cost/o | Rib | Intercostal (between the ribs) |
| col/o | Colon | Colitis (inflammation of the colon) |
| hyster/o | Uterus | Hysterectomy (surgical removal of the uterus) |
| mast/o, mamm/o | Breast | Mastectomy, Mammogram |
| thyr/o | Thyroid | Thyroidectomy (removal of the thyroid) |
| chole/o | Bile, gallbladder | Cholecystectomy (removal of the gallbladder) |
Essential Suffixes
Suffixes Indicating Conditions or Diseases
| Suffix | Meaning | Example Term | Definition |
|---|---|---|---|
| -itis | Inflammation | Bronchitis | Inflammation of the bronchi |
| -osis | Abnormal condition | Cyanosis | Abnormal blue discoloration |
| -pathy | Disease, suffering | Neuropathy | Disease of the nerves |
| -algia | Pain | Myalgia | Muscle pain |
| -emia | Blood condition | Anemia | Deficiency of red blood cells |
| -uria | Urine condition | Hematuria | Blood in the urine |
| -penia | Deficiency | Leukopenia | Deficiency of white blood cells |
| -megaly | Enlargement | Hepatomegaly | Enlargement of the liver |
| -malacia | Softening | Osteomalacia | Softening of the bones |
| -stenosis | Narrowing | Stenosis | Narrowing of a vessel or passage |
Suffixes Indicating Procedures
| Suffix | Meaning | Example Term | Definition |
|---|---|---|---|
| -ectomy | Surgical removal | Appendectomy | Removal of the appendix |
| -otomy | Surgical incision (cutting into) | Tracheotomy | Incision into the trachea |
| -ostomy | Creating an artificial opening | Colostomy | Artificial opening in the colon |
| -plasty | Surgical repair | Rhinoplasty | Surgical repair/reshaping of the nose |
| -scopy | Visual examination | Colonoscopy | Visual examination of the colon |
| -graphy | Process of recording | Mammography | Process of recording breast images |
| -gram | Record or image | Electrocardiogram | Record of heart electrical activity |
| -centesis | Surgical puncture to remove fluid | Thoracentesis | Puncture of the chest wall to remove fluid |
Suffixes Indicating Descriptions
| Suffix | Meaning | Example Term | Definition |
|---|---|---|---|
| -ic, -al, -ous, -ary | Pertaining to | Cardiac, renal, venous, pulmonary | Pertaining to the heart, kidney, vein, lung |
| -logist | Specialist who studies | Cardiologist | Specialist who studies the heart |
| -logy | Study of | Cardiology | Study of the heart |
| -genesis | Origin, formation | Pathogenesis | Origin/development of disease |
Putting It All Together: Decoding Medical Terms
Example 1: Electrocardiogram
- Electr/o = electrical
- Cardi/o = heart
- -gram = record
- Meaning: A record of the electrical activity of the heart (EKG/ECG)
Example 2: Cholecystectomy
- Chole = bile/gallbladder
- Cyst/o = bladder/sac
- -ectomy = surgical removal
- Meaning: Surgical removal of the gallbladder
Example 3: Dysmenorrhea
- Dys- = difficult, painful
- Men/o = menstruation
- -rrhea = flow, discharge
- Meaning: Painful menstruation
Example 4: Hyperglycemia
- Hyper- = excessive, above normal
- Glyc/o = sugar, glucose
- -emia = blood condition
- Meaning: Excessive sugar in the blood (high blood sugar)
Test Your Knowledge
The medical term "bradycardia" can be broken down into which components?
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Test Your Knowledge
A patient is scheduled for a "cholecystectomy." Based on medical terminology word parts, what procedure is being performed?
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Test Your Knowledge
When building a medical term, when should the combining vowel "o" be DROPPED?
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Test Your Knowledge
A medical record notes that a patient has "hepatomegaly." What does this term mean?
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