Medical Terminology for Interpreters: The Terms That Actually Come Up on Calls

You’re mid-call. The provider says “We’re going to do a cholecystectomy.” You’ve never heard the word before. You freeze for half a second — which on a live call feels like ten — and your brain scrambles to break it down. Chole… cyst… ectomy. Gallbladder removal. You say it. The call moves on.

That half-second is the difference between a smooth interpretation and a stumble that shakes your confidence for the next three calls. Medical terminology isn’t optional in this work. It’s load-bearing. And the interpreters who build their vocabulary systematically — instead of learning every term the hard way on a live call — handle the pressure better.

This post covers the terms that actually come up in OPI medical calls. Not a 2,000-entry dictionary. The stuff you’ll hear this week.

Why Greek and Latin Roots Are Your Best Shortcut

You don’t need to memorize every medical term. You need to learn the system they’re built from.

Almost all medical terminology comes from Greek and Latin roots, prefixes, and suffixes. Once you know the pieces, you can decode terms you’ve never seen before — on the fly, mid-call, without looking anything up.

Here are the building blocks that show up constantly:

Prefixes (what/where):

Prefix	Meaning	Example
hyper-	excessive, above	hypertension (high blood pressure)
hypo-	below, deficient	hypoglycemia (low blood sugar)
tachy-	fast	tachycardia (fast heart rate)
brady-	slow	bradycardia (slow heart rate)
dys-	difficult, painful	dyspnea (difficulty breathing)
poly-	many	polyuria (excessive urination)
hemi-	half	hemiplegia (paralysis of one side)

Suffixes (what’s happening):

Suffix	Meaning	Example
-itis	inflammation	appendicitis, bronchitis
-ectomy	surgical removal	cholecystectomy (gallbladder removal)
-otomy	cutting into	tracheotomy (cutting into the trachea)
-ostomy	creating an opening	colostomy (opening in the colon)
-osis	abnormal condition	cirrhosis, stenosis
-emia	blood condition	anemia, septicemia
-algia	pain	myalgia (muscle pain), neuralgia
-pathy	disease	neuropathy, cardiomyopathy

Learn these and you’ll decode 60-70% of unfamiliar terms on the spot. The NCIHC’s “Terminology of Health Care Interpreting” glossary is worth bookmarking as a deeper reference.

Learn the roots and you stop memorizing words. You start reading them.

The 10 Body Systems You Need Cold

Providers organize their thinking by body systems. So should you. Here are the ten you’ll encounter on medical OPI calls, with the terms that show up most in each.

1. Integumentary (skin, hair, nails): lesion, rash, laceration, abrasion, abscess, biopsy, dermatitis, edema, wound dehiscence.

2. Musculoskeletal (bones, joints, muscles): fracture, sprain, strain, range of motion (ROM), joint aspiration, arthritis, osteoporosis, tendinitis, orthopedic.

3. Circulatory (heart, blood vessels): hypertension, arrhythmia, myocardial infarction (MI), congestive heart failure (CHF), embolism, thrombosis, varicose veins, angioplasty, stent.

4. Respiratory (lungs, airways): dyspnea, pneumonia, COPD, bronchitis, asthma exacerbation, intubation, pulse oximetry (SpO2), nebulizer, spirometry.

5. Nervous (brain, spinal cord, nerves): seizure, stroke (CVA), neuropathy, concussion, syncope (fainting), lumbar puncture, EEG, paresthesia (tingling/numbness).

6. Endocrine (hormones, glands): diabetes mellitus (Type 1, Type 2), insulin, thyroid (hyper/hypo), A1C, glucose, cortisol, endocrinologist.

7. Immune/Lymphatic: autoimmune, immunosuppressant, lymph nodes, biopsy, CBC (complete blood count), WBC (white blood cell count), allergic reaction, anaphylaxis.

8. Digestive (GI): GERD, colonoscopy, endoscopy, bowel obstruction, appendicitis, hepatitis, cirrhosis, NPO (nothing by mouth), NG tube (nasogastric).

9. Urinary: UTI (urinary tract infection), catheter, dialysis, creatinine, BUN, renal failure, nephrologist, urinalysis.

10. Reproductive: OB/GYN, prenatal, trimester, cervical dilation, cesarean section (C-section), ectopic pregnancy, mammogram, Pap smear.

You don’t need to know everything about each system. You need to know the terms well enough to interpret them without hesitation when they come up at speed.

Medications, Dosages, and Routes

This is where mistakes get dangerous. Misinterpreting “25 milligrams” as “250 milligrams” or confusing “twice daily” with “three times daily” has real consequences for patients. These terms come up on nearly every medical OPI call.

Medications you’ll hear constantly:

• Metoprolol — beta blocker for blood pressure/heart rate
• Lisinopril — ACE inhibitor for blood pressure
• Metformin — first-line diabetes medication
• Omeprazole — proton pump inhibitor for acid reflux
• Amlodipine — calcium channel blocker for blood pressure
• Levothyroxine — thyroid hormone replacement

You don’t need to know the pharmacology. You need to pronounce them correctly and interpret them accurately.

Dosage abbreviations that trip people up:

Abbreviation	Meaning	What you’ll hear
BID	Twice a day	”Take this BID”
TID	Three times a day	”TID with meals”
QID	Four times a day	Less common but it comes up
QHS	At bedtime	”Take QHS” (quaque hora somni)
PRN	As needed	”Tylenol PRN for pain”
QD	Once daily	”Metformin 500mg QD”
AC	Before meals	”Insulin AC”
PC	After meals	”Take PC”

Routes of administration:

Abbreviation	Meaning
PO	By mouth (per os)
IV	Intravenous
IM	Intramuscular
SQ / SubQ	Subcutaneous (under the skin)
PR	Per rectum
SL	Sublingual (under the tongue)
INH	Inhaled

The Confusing Pairs That Trip Everyone Up

These are the terms that catch even experienced interpreters. They sound similar, look similar on paper, and mean very different things.

Hyper- vs. Hypo-: Hypertension is high blood pressure. Hypotension is low blood pressure. Hyperglycemia is high blood sugar. Hypoglycemia is low blood sugar. One letter difference, opposite clinical situations. If you mix these up on a diabetes call, the patient could take the wrong action.

-ectomy vs. -otomy vs. -ostomy: An -ectomy removes something (appendectomy = removing the appendix). An -otomy cuts into something (tracheotomy = cutting into the trachea, usually temporary). An -ostomy creates a permanent or semi-permanent opening (colostomy = creating an opening in the colon to the surface of the body). Providers use these interchangeably in casual speech, but they’re not the same procedure.

Ileum vs. Ilium: The ileum is part of the small intestine. The ilium is part of the hip bone. You’ll hear these in very different contexts, but on a phone call with poor audio, they sound identical.

Ureter vs. Urethra: The ureter connects the kidney to the bladder. The urethra connects the bladder to the outside. Both come up in urology calls. Both sound almost the same over the phone.

Abduction vs. Adduction: Abduction moves a limb away from the body. Adduction moves it toward the body. Physical therapy and orthopedic calls use these constantly.

Palpation vs. Palpitation: Palpation is the provider pressing on the body to examine it. Palpitation is the patient’s heart racing or fluttering. You’ll hear both on the same call sometimes.

Discharge Instructions: Where Most OPI Interpreters Struggle

Discharge is the single most terminology-dense moment in any medical call. The provider is covering medications, follow-up appointments, warning signs, activity restrictions, wound care, and dietary instructions — often in one long stretch.

A typical discharge instruction sounds like this: “Take Metoprolol 25 milligrams PO BID with food. Follow up with your PCP in seven days. If you experience chest pain, shortness of breath, or dizziness, go to the ER. No heavy lifting over ten pounds for two weeks. Keep the incision clean and dry.”

That’s five different categories of information in thirty seconds. On the phone, with no visual reference, interpreting it cleanly requires you to know every term before you hear it. Discharge is not where you want to encounter a word for the first time.

CCHI offers mini-glossaries organized by appointment type — including discharge — with 50 to 101 terms each. They’re free and built for exactly this situation. Download them.

Vital Signs, Labs, and Imaging

These come up on almost every call and providers rattle them off fast.

Vital signs: blood pressure (systolic/diastolic), heart rate (HR), respiratory rate (RR), temperature, oxygen saturation (SpO2), pain scale (0-10).

Common lab values: CBC (complete blood count), BMP (basic metabolic panel), CMP (comprehensive metabolic panel), A1C, TSH (thyroid-stimulating hormone), INR (blood clotting measure), lipid panel, urinalysis.

Imaging: X-ray, CT scan (computed tomography), MRI (magnetic resonance imaging), ultrasound, PET scan, mammogram, fluoroscopy, DEXA scan (bone density).

Providers rarely explain what these abbreviations mean — they assume everyone in the conversation knows. On an OPI call, you’re the one who needs to bridge that gap and render it in terms the patient can understand.

Mental Status and Consent Language

Behavioral health and psychiatric calls are increasing in OPI volume. And consent conversations happen on nearly every procedural call.

Mental status terms: oriented (to person, place, time, situation), affect (flat, blunted, labile), ideation (suicidal ideation, homicidal ideation), psychosis, delusion, hallucination (auditory, visual), cognition, competency.

Consent language: informed consent, risks and benefits, alternatives, right to refuse, capacity to consent, advance directive, power of attorney (POA), healthcare proxy, DNR (do not resuscitate), POLST (Physician Orders for Life-Sustaining Treatment).

Consent calls are high-stakes. The patient is deciding whether to agree to a procedure, and every word matters legally. If you’re unclear on any term during a consent conversation, stop and ask. The NIH’s health information resources are a good reference for patient-facing explanations of medical concepts.

Building Your Personal Glossary

The interpreters who grow fastest are the ones who build a personal glossary — not a list they downloaded, but one they build from terms they actually encountered on calls.

After every shift, write down the terms that gave you trouble. Look them up. Add them to a spreadsheet or notebook with the term, its meaning, and equivalent terms in your target language. Review it before your next shift. If you want a step-by-step system for this, read our guide on building a glossary bank.

This sounds basic. It is. It’s also what separates interpreters who plateau after six months from interpreters who keep getting sharper for years.

If you’re working toward medical interpreter certification, building your glossary now doubles as exam prep. And understanding what you can and can’t share from those calls is just as important — make sure you’re solid on HIPAA requirements for interpreters.

You Don’t Need to Know Everything. You Need a System.

Nobody walks into their first OPI shift knowing every medical term. The providers you interpret for spent a decade learning this vocabulary. You’re expected to keep up with a fraction of the training and no prep time.

The edge isn’t memorizing more words. It’s having a system: learn the roots so you can decode on the fly, study by body system so your knowledge has structure, drill the high-stakes terms (meds, dosages, routes) until they’re automatic, and build a personal glossary from real calls so your study time targets your actual gaps. For a broader look at the tools that help with prep and live calls, see The Interpreter’s Toolkit.

Medical terminology is the foundation. Build it deliberately and every call gets a little easier.

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Related reading:

• How to Become a Medical Interpreter: The Honest Guide
• HIPAA for Interpreters: What You Actually Need to Know
• Interpreter Burnout: Why OPI Burns You Out Faster (and What Actually Helps)
• Note-Taking for OPI: Why Everything You Learned in Training Doesn’t Work