A medical prefix sits at the start of a term and changes its meaning, often by telling you where, how much, how fast or when (for example, hyper- means above normal). A suffix sits at the end and usually names the condition, procedure or specialty (for example, -itis means inflammation). Learn the common ones below and you can work out the meaning of thousands of medical terms instead of memorizing each one.
This guide is based on the prefixes and suffixes chapter of our Medical Terminology textbook, written by doctors, with more than 100,000 copies sold. Each list gives the meaning and a real example, and there is a short quiz at the end so you can test yourself.
Free printable: download the 2-page medical prefixes and suffixes cheat sheet (PDF) to study offline or keep next to your notes.
In this guide:
- How medical terms are built
- Common medical prefixes
- Common medical suffixes
- Opposite pairs and look-alike word parts
- Quick quiz
- How to memorize them
- Frequently asked questions
How Medical Terms Are Built
Most medical terms combine up to three kinds of word parts:
- Prefix (beginning): changes or adds to the meaning, e.g. peri- = around.
- Word root (core meaning): usually a body part or substance, e.g. card or cardi = heart.
- Suffix (ending): the condition, procedure or type of word, e.g. -itis = inflammation.
A combining vowel, usually o, links a root to another root or to a suffix that starts with a consonant. A root plus its combining vowel is called a combining form (written gastr/o). The vowel is usually dropped before a suffix that starts with a vowel (gastroscopy keeps it, gastritis does not), but it stays between two roots even when the second root starts with a vowel (gastroenteritis).
Four Terms, Broken Down
- Pericarditis = peri- (around) + card (heart) + -itis (inflammation): inflammation of the pericardium, the sac around the heart.
- Hypoglycemia = hypo- (below) + glyc (sugar) + -emia (blood condition): low blood sugar.
- Bradycardia = brady- (slow) + card (heart) + -ia (condition): a slow heart rate.
- Gastroenteritis = gastr/o (stomach) + enter (intestine) + -itis (inflammation): inflammation of the stomach and intestines.
A useful habit: read the suffix first, then the prefix, then the root. "Inflammation... around... the heart" quickly becomes pericarditis.
Common Medical Prefixes and Their Meanings
Prefixes for "Without," "Against," "Bad" and "Good"
- a-, an-: without, absence of. Apnea: a temporary stop in breathing.
- anti-: against. Antiemetic: a drug that prevents or treats vomiting.
- contra-: against, opposite. Contraception: prevention of pregnancy.
- dys-: difficult, painful, abnormal. Dysphagia: difficulty swallowing.
- mal-: bad, poor. Malabsorption: poor absorption of nutrients from the intestine.
- eu-: normal, good. Eupnea: normal, quiet breathing.
Prefixes for Amount and Size
- hyper-: above normal, excessive. Hyperglycemia: high blood sugar.
- hypo-: below normal, deficient. Hypothyroidism: an underactive thyroid gland.
- macro-: large. Macrocephaly: an abnormally large head.
- micro-: small. Microcephaly: an abnormally small head.
- poly-: many, much. Polyuria: passing an abnormally large amount of urine.
- olig-, oligo-: few, scanty. Oliguria: passing an abnormally small amount of urine.
- pan-: all. Pancytopenia: low levels of all three types of blood cells.
Prefixes for Position and Direction
- ab-: away from. Abduction: movement of a limb away from the body's midline.
- ad-: toward. Adduction: movement of a limb toward the midline.
- endo-: within, inside. Endoscopy: looking inside the body with an instrument.
- exo-: outside, outward. Exocrine: secreting outward through a duct.
- epi-: upon, above. Epigastric: over the stomach, in the upper middle part of the abdomen.
- sub-: below, under. Sublingual: under the tongue.
- supra-: above. Suprapubic: above the pubic bone.
- infra-: below. Infraorbital: below the eye socket.
- inter-: between. Intercostal: between the ribs.
- intra-: within. Intravenous: within a vein.
- peri-: around. Pericardium: the sac around the heart.
- circum-: around. Circumoral: around the mouth.
- para-: beside, near; also beyond or abnormal. Paranasal sinuses: air-filled spaces in the bones around the nose.
- retro-: behind, backward. Retroperitoneal: behind the peritoneum.
- trans-: across, through. Transdermal: through the skin.
Prefixes for Time and Speed
- brady-: slow. Bradycardia: a slow heart rate.
- tachy-: fast. Tachycardia: a fast heart rate.
- pre-: before. Prenatal: before birth.
- post-: after. Postprandial: after a meal.
- neo-: new. Neonate: a newborn baby.
Prefixes for Numbers
- mono-, uni-: one. Unilateral: on one side.
- bi-, di-: two. Bilateral: on both sides. Diplegia: paralysis of matching parts on both sides of the body, such as both legs.
- tri-: three. Tricuspid valve: the valve between the right atrium and right ventricle, named for its three cusps.
- quadri-, tetra-: four. Quadriplegia: paralysis of all four limbs.
- hemi-, semi-: half. Hemiplegia: paralysis of one side of the body.
- nulli-: none. Nullipara: a woman who has never given birth.
- primi-: first. Primigravida: a woman pregnant for the first time.
Word Parts for Colors
Strictly speaking these are combining forms, but they often appear at the start of a term and are learned alongside prefixes:
- erythr/o: red. Erythrocyte: red blood cell.
- leuk/o: white. Leukocyte: white blood cell.
- melan/o: black, dark. Melanocyte: a cell that produces the dark pigment melanin.
- cyan/o: blue. Cyanosis: bluish skin caused by low oxygen in the blood.
- xanth/o: yellow. Xanthoma: a yellowish deposit of fat under the skin.
Common Medical Suffixes and Their Meanings
Suffixes for Conditions and Symptoms
- -itis: inflammation. Appendicitis: inflammation of the appendix.
- -osis: condition, often abnormal. Thrombosis: a condition in which a blood clot forms inside a vessel.
- -emia: blood condition. Anemia: a lack of red blood cells or hemoglobin.
- -algia, -dynia: pain. Arthralgia: joint pain. Gastrodynia: stomach pain.
- -megaly: enlargement. Hepatomegaly: an enlarged liver.
- -oma: tumor, mass (benign or malignant). Lipoma: a benign fatty tumor.
- -pathy: disease. Neuropathy: disease of the nerves.
- -penia: deficiency. Leukopenia: a low white blood cell count.
- -plegia: paralysis. Paraplegia: paralysis of both legs and the lower body.
- -ptosis: drooping, sagging. Blepharoptosis: a drooping upper eyelid.
- -malacia: softening. Osteomalacia: softening of the bones.
- -sclerosis: hardening. Arteriosclerosis: hardening of the arteries.
- -stenosis: narrowing. Arteriostenosis: narrowing of an artery.
- -rrhea: flow, discharge. Rhinorrhea: a runny nose.
- -rrhage, -rrhagia: bursting forth, excessive bleeding. Hemorrhage: heavy bleeding.
- -lith, -lithiasis: stone, presence of stones. Nephrolithiasis: kidney stones.
- -cele: hernia, protrusion. Cystocele: the bladder bulging into the vagina through a weakened front vaginal wall.
- -uria: urine condition. Hematuria: blood in the urine.
- -lysis: breakdown, destruction. Hemolysis: breakdown of red blood cells.
- -spasm: sudden involuntary contraction. Bronchospasm: sudden tightening of the airway muscles.
Suffixes for Procedures and Tests
- -ectomy: surgical removal. Appendectomy: removal of the appendix.
- -tomy: cutting into, incision. Tracheotomy: an incision into the windpipe.
- -stomy: surgically creating an opening. Colostomy: an opening from the colon through the abdominal wall.
- -plasty: surgical repair or reshaping. Rhinoplasty: surgery to reshape the nose.
- -rrhaphy: surgical suturing. Herniorrhaphy: repair of a hernia with sutures.
- -pexy: surgical fixation. Nephropexy: surgically fixing a loose kidney in place.
- -desis: surgical fusion. Arthrodesis: fusing the bones of a joint.
- -centesis: puncture to remove fluid. Amniocentesis: removing a sample of amniotic fluid with a needle.
- -tripsy: crushing. Lithotripsy: breaking up stones, for example with shock waves.
- -scopy: visual examination with an instrument. Colonoscopy: examination of the colon.
- -scope: instrument for viewing. Otoscope: instrument for examining the ear.
- -graphy: process of recording an image or tracing. Mammography: X-ray imaging of the breast.
- -gram: the record or image produced. Electrocardiogram: the tracing of the heart's electrical activity.
- -metry, -meter: measurement, measuring instrument. Spirometry: measuring how much air you breathe in and out, and how fast you can breathe out.
- -opsy: viewing, examination. Biopsy: removing a tissue sample to examine it.
Suffixes That Mean "Pertaining To"
These turn a root into an adjective: -ac (cardiac, pertaining to the heart), -al (renal, kidney), -ar (muscular, muscle), -ary (pulmonary, lungs), -eal (esophageal, esophagus), -ic (gastric, stomach) and -ous (venous, veins).
Suffixes for Specialties and Specialists
- -logy: study of. Cardiology: the study and treatment of the heart.
- -logist: specialist in a field of study. Cardiologist: a heart specialist.
- -iatry: medical treatment, field of medicine. Psychiatry: the medical treatment of mental disorders.
- -iatrics: field of medicine. Pediatrics: the care of children.
- -ician, -ist: practitioner. Pediatrician, pharmacist.
Suffixes Meaning "Small"
-ole (arteriole, a small artery), -ule (venule, a small vein) and -icle (ossicle, a small bone, such as those in the middle ear).
Opposite Pairs: Learn Them Together
Many prefixes come in pairs with opposite meanings. Learning them side by side halves the work and prevents classic mix-ups:
- hyper- (above normal) and hypo- (below normal): hyperglycemia and hypoglycemia.
- tachy- (fast) and brady- (slow): tachycardia and bradycardia.
- ab- (away from) and ad- (toward): abduction and adduction.
- endo- (within) and exo- (outside): endocrine and exocrine glands.
- eu- (normal) and dys- (abnormal, difficult): eupnea and dyspnea.
- pre- (before) and post- (after): preoperative and postoperative.
Look-Alike Word Parts That Trip Students Up
- -ectomy, -tomy and -stomy: removing (appendectomy), cutting into (tracheotomy) and making an opening (tracheostomy, colostomy).
- -rrhea, -rrhage, -rrhaphy and -rrhexis: flow (diarrhea), bursting forth or bleeding (hemorrhage), suturing (herniorrhaphy) and rupture (amniorrhexis, rupture of the amniotic membranes).
- inter- and intra-: between (intercostal, between the ribs) and within (intravenous, within a vein).
- -scope, -scopy and -gram, -graphy: the instrument or record versus the process (otoscope and otoscopy; mammogram and mammography).
Greek and Latin Twins
Because medical language draws on both Greek and Latin, some body parts have two word parts with the same meaning. Clinicians use both:
- Kidney: nephr/o (Greek, nephrology) and ren/o (Latin, renal).
- Breast: mast/o (Greek, mastectomy) and mamm/o (Latin, mammography).
- Tooth: odont/o (Greek, orthodontics) and dent/o (Latin, dental).
- Navel: omphal/o (Greek, omphalocele) and umbilic/o (Latin, umbilical).
Quick Quiz: Test Yourself
- What does the suffix -itis mean?
- What does tachycardia mean?
- Which suffix means surgical removal?
- What does the prefix inter- mean?
- Hepat/o means liver. What is hepatomegaly?
- Which prefix means "without"?
- What does -rrhaphy mean?
- Phag/o refers to eating or swallowing. What is dysphagia?
- What color does cyan/o refer to?
- Which word means "pertaining to the heart": cardiac or cardiology?
Answers: 1. Inflammation. 2. A fast heart rate. 3. -ectomy. 4. Between. 5. An enlarged liver. 6. a- or an-. 7. Surgical suturing. 8. Difficulty swallowing. 9. Blue. 10. Cardiac (cardiology is the study of the heart).
For a longer test, try our free 50-question medical terminology quiz with answers.
Want more practice? Our Medical Terminology Workbook is an exercise-only companion with matching columns, fill-in-the-blank questions, multiple-choice questions, true or false and picture labeling.
How to Memorize Prefixes and Suffixes
- Learn them in groups by meaning (position, number, color) rather than alphabetically.
- Use flashcards with spaced repetition: review at increasing intervals and spend more time on the cards you miss.
- Break down every new term you meet in lectures, textbooks and patient notes. Each one reinforces the word parts.
- Test yourself instead of rereading: recalling the answer is what makes it stick.
For more techniques, see our guides 10 Strategies to Memorize Medical Terminology and Mastering Medical Terminology. The U.S. National Library of Medicine also offers a free Understanding Medical Words tutorial.
Frequently Asked Questions
What is the difference between a prefix and a suffix in medical terminology?
A prefix comes before the word root and usually describes position, number, time or amount (for example, sub- = below). A suffix comes after the root and usually names a condition, procedure or specialty, or turns the term into an adjective (for example, -ectomy = surgical removal).
What is the medical suffix for pain?
-algia and -dynia both mean pain, as in arthralgia (joint pain) and gastrodynia (stomach pain).
What is the medical suffix for inflammation?
-itis, as in tonsillitis, arthritis and dermatitis.
What is the difference between -ectomy, -tomy and -stomy?
-ectomy means removing something (appendectomy), -tomy means cutting into it (tracheotomy) and -stomy means creating an opening (colostomy).
What is a combining form?
A combining form is a word root plus a combining vowel, usually o, such as cardi/o or gastr/o. It lets a root join another root or a suffix that starts with a consonant.
What is the fastest way to learn medical prefixes and suffixes?
Learn them in meaningful groups, practice with flashcards and self-testing over several days rather than in one long session, and break down real terms as you meet them. A structured textbook and workbook help you cover the most common word parts in a logical order.
Keep Going
Prefixes and suffixes are the fastest route into medical language. To learn them step by step, with roots, pronunciation, body-system terms and exercises with answers, see our Medical Terminology textbook and the companion Medical Terminology Workbook, or take our self-paced Medical Terminology Course. You can see all our books on our Textbooks page.