Medical Terminology Cheat Sheet for Nursing Students
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You're sitting in clinical and the doctor says hepatosplenomegaly.
Everyone nods. You nod. Inside you have absolutely no idea what just happened.
That's what medical terminology feels like in the beginning — like a foreign language nobody officially taught you. But here's the thing: it is a foreign language. Latin and Greek, to be exact. And once you learn the rules, you can decode almost any medical word you'll ever see — without memorizing each one individually.
This is that lesson.
How Medical Words Are Built
Every medical word is made of up to three parts:
- Prefix — comes before the root. Tells you number, direction, or intensity.
- Root word — the core meaning. Usually refers to a body part or system.
- Suffix — comes after the root. Tells you what's happening — a condition, procedure, or process.
So hepatosplenomegaly breaks down like this:
- hepato = liver
- spleno = spleen
- -megaly = enlargement
Enlarged liver and spleen. That's it. Once you see the pattern, the word makes complete sense.
The 20 Most Important Prefixes in Nursing
| Prefix | Meaning | Example |
|---|---|---|
| brady- | slow | bradycardia — slow heart rate |
| tachy- | fast | tachycardia — fast heart rate |
| hyper- | above / excessive | hypertension — high blood pressure |
| hypo- | below / deficient | hypoglycemia — low blood sugar |
| dys- | difficult / painful | dyspnea — difficulty breathing |
| epi- | upon / above | epidermis — outer layer of skin |
| hemi- | half | hemiplegia — paralysis of one side |
| poly- | many / excessive | polyuria — excessive urination |
| neo- | new | neonatal — newborn period |
| pre- | before | prenatal — before birth |
| post- | after | postoperative — after surgery |
| bi- | two | bilateral — both sides |
| macro- | large | macrocytic — abnormally large cells |
| micro- | small | microscopic — too small to see |
| anti- | against | antibiotic — against bacteria |
| inter- | between | intercostal — between the ribs |
| intra- | within | intravenous — within the vein |
| peri- | around | pericardium — around the heart |
| sub- | under / below | subcutaneous — under the skin |
| trans- | across / through | transdermal — through the skin |
The 20 Most Important Suffixes in Nursing
| Suffix | Meaning | Example |
|---|---|---|
| -itis | inflammation | appendicitis — inflammation of appendix |
| -emia | blood condition | anemia — low red blood cells |
| -oma | tumor / mass | carcinoma — cancerous tumor |
| -pathy | disease | neuropathy — nerve disease |
| -ectomy | surgical removal | appendectomy — removal of appendix |
| -ostomy | surgical opening | colostomy — opening in colon |
| -otomy | surgical incision | tracheotomy — incision in trachea |
| -scopy | visual examination | colonoscopy — exam of colon |
| -plasty | surgical repair | rhinoplasty — nose repair |
| -algia | pain | neuralgia — nerve pain |
| -megaly | enlargement | cardiomegaly — enlarged heart |
| -stenosis | narrowing | aortic stenosis — narrowed aortic valve |
| -lysis | breakdown / destruction | hemolysis — breakdown of red blood cells |
| -rrhea | flow / discharge | diarrhea — frequent loose stools |
| -rrhage | excessive bleeding | hemorrhage — heavy bleeding |
| -gram | record / image | electrocardiogram — heart recording |
| -graphy | process of recording | radiography — X-ray imaging |
| -logy | study of | cardiology — study of the heart |
| -pnea | breathing | apnea — absence of breathing |
| -uria | urine condition | hematuria — blood in urine |
How to Decode Any Medical Word in 3 Steps
When you see a word you've never seen before, do this:
- Find the suffix first — it tells you what's happening (condition, procedure, or process)
- Find the prefix — it modifies the root (how much, where, which direction)
- Identify the root — it tells you what body part or system is involved
Example: Tachycardia
- Suffix: none (it ends in the root)
- Prefix: tachy- = fast
- Root: -cardia = heart
- Result: fast heart rate ✓
Example: Cholecystectomy
- Suffix: -ectomy = surgical removal
- Root: cholecyst = gallbladder
- Result: surgical removal of the gallbladder ✓
The Combining Vowel Rule
When two root words are joined together, a combining vowel — usually o — is added between them to make pronunciation easier.
That's why it's electrocardiogram, not electriccardiogram. The o is just there to make it flow.
This rule explains why so many medical words look longer than they need to be — they're just two roots joined with a vowel.
Want the Full Reference Guide?
This post covers the essentials — but nursing school goes deeper. Our Medical Terminology Study Guide covers:
- 50+ prefixes organized A–Z with clinical examples
- 20+ procedure suffixes and condition suffixes
- Root words organized by body system
- Directional terms, body planes, and abdominal regions
- Common abbreviations used on every shift
- Quick reference sheet + 10 NCLEX-style practice questions with full rationales
16 pages. Instant PDF download. $5.99.