On 11 March 2020 the World Health Organization described COVID-19 as a pandemic. Few people stopped to parse the word, but it's Greek: pan, "all", and demos, "people". A disease of all the people. That one prefix, pan-, tells you most of what the word means before you know anything else about it.
Medical prefixes work like that. Learn a few dozen and a great many terms take themselves apart. This deck marks every prefix as Greek or Latin, because the split matters: in medicine, Greek wins most of the time.
Why most medical prefixes are Greek
The early Greek medical writers, above all the Hippocratic texts, named many conditions, and later physicians writing in Latin kept those names and coined new ones from Greek on the same pattern. Latin still dominates anatomy (the body-parts deck in this unit: renal, pulmonary), but for prefixes describing speed, amount, position and disorder, expect Greek. I'm simplifying: plenty of Latin prefixes are in clinical use too, such as intra- (intravenous) and sub- (subcutaneous).
Speed, amount and size
- brady- (Greek), slow: bradycardia
- tachy- (Greek), fast: tachycardia
- hyper- (Greek), above or too much: hyperglycemia
- hypo- (Greek), below or too little: hypoglycemia, hypothermia
- poly- (Greek), many or much: polyuria, polydipsia
- micro- and macro- (Greek), small and large: microcytic, macrophage
In adults, a resting heart rate under 60 beats a minute is usually called bradycardia and one over 100 tachycardia. Those cut-offs are conventions, and they differ for children.
Position: where it is
- endo- (Greek), within: endoscopy, endocardium
- ecto- (Greek), outside: ectoderm
- epi- (Greek), upon: epidermis, epigastric
- peri- (Greek), around: pericardium, periodontal
- para- (Greek), beside: parathyroid
- infra- (Latin), below: infraorbital
- supra- (Latin), above: suprapubic
Para- has a second sense, "abnormal" or "faulty", as in paresthesia, an abnormal tingling sensation. Context tells you which one you have.
Absence, difficulty and the normal state
- a-, an- (Greek), without: apnea, anemia, anesthesia
- dys- (Greek), bad or difficult: dyspnea, dysphagia
- eu- (Greek), good or normal: eupnea, euthyroid
These three make a neat set for breathing: apnea is no breathing, dyspnea is difficult breathing, eupnea is normal breathing. British spelling keeps the older vowels in some of these words: anaemia, dyspnoea.
Greek and Latin twins
| Meaning | Greek | Latin |
|---|---|---|
| around | peri- (pericardium) | circum- (circumference) |
| many | poly- (polyuria) | multi- (multifocal) |
| above, over | hyper- (hypertension) | super- (superior) |
| below, under | hypo- (hypodermic) | sub- (subcutaneous) |
| within | endo- (endoscopy) | intra- (intravenous) |
| half | hemi- (hemiplegia) | semi- (semicircle) |
| without, not | a-, an- (apnea) | in- (insomnia) |
Medicine also mixes the two inside one word. Hypertension is Greek hyper- on Latin tensio; neonatal is Greek neo- on Latin natalis.
Common mistakes
- Swapping hyper- and hypo-. Hyper- is too much, hypo- too little. Hypoglycemia is low blood sugar.
- Spelling dys- as dis-. Dys- is Greek, "bad, difficult": dysfunction. Dis- is Latin, "apart": dissect. They are different prefixes.
- Reading para- only as "beside". In paresthesia it means abnormal.
- Treating the heart-rate cut-offs as fixed rules. They are adult conventions, not a diagnosis.
Frequently asked questions
Are medical prefixes Greek or Latin?
Both, but most of the common ones (hyper-, hypo-, brady-, tachy-, dys-, peri-, endo-) are Greek. Latin prefixes such as sub-, intra-, infra- and supra- are common in anatomy.
What is the difference between hyper- and hypo-?
Hyper- means above or too much, and hypo- means below or too little. Both are Greek.
What does the prefix dys- mean in medical terms?
Bad, difficult or painful, as in dyspnea (difficult breathing) and dysphagia (difficulty swallowing).
What does brady- mean?
Slow, from Greek bradys. Bradycardia is a slow heart rate.
Try it
Say whether each prefix is Greek or Latin before you flip the card. Then recall: which Greek prefix, meaning "around", names the sac that surrounds the heart?