10 Common Errors Made by Medical Interpreters (And How to Avoid Them)
Even trained medical interpreters make errors — and in healthcare, those errors can be dangerous. Understanding common mistakes helps providers recognize problems, choose quality interpreters, and ensure patient safety.
⚡ Key Error Categories
- Omissions — Leaving out information
- Additions — Adding information not said
- Substitutions — Changing the meaning
- Role confusion — Acting as advocate instead of interpreter
- Vocabulary errors — Using wrong medical terms
Why Interpreter Errors Matter
In healthcare settings, interpreter errors can lead to:
- Misdiagnosis — Wrong symptoms reported, wrong diagnosis given
- Medication errors — Wrong dosages, wrong medications, drug interactions
- Invalid informed consent — Patient didn’t actually understand
- Missed follow-up — Instructions weren’t clearly conveyed
- Delayed treatment — Critical information not communicated
- Patient harm or death — In worst cases
Research has documented that interpreter errors occur in a significant percentage of medical encounters — even with trained interpreters. The key is minimizing errors and catching them before they cause harm.
The 10 Most Common Medical Interpreter Errors
1. Omissions
What it is: Leaving out part of what was said.
Example: Doctor says: “Take this medication twice a day with food, and call us if you experience any dizziness, nausea, or shortness of breath.”
Interpreter says: “Take this medication twice a day.”
The interpreter omitted critical information about food timing and warning signs.
Why it happens: Message too long to remember, interpreter assumes it’s not important, time pressure, or lack of medical knowledge.
2. Additions
What it is: Adding information that wasn’t said.
Example: Patient says: “I’ve been feeling tired.”
Interpreter says: “She’s been feeling tired. She’s probably anemic — she looks pale to me.”
The interpreter added their own medical opinion, which isn’t their role.
Why it happens: Wanting to be helpful, cultural norms of elaboration, or confusion about the interpreter’s role.
3. Substitutions/Changes
What it is: Changing the meaning of what was said.
Example: Patient says: “I take this medication sometimes when I remember.”
Interpreter says: “She takes the medication regularly.”
The interpreter changed “sometimes” to “regularly” — a critical difference for medication adherence.
Why it happens: Trying to make the patient “look good,” cultural embarrassment, or not recognizing the clinical significance.
4. Editorialization
What it is: Adding personal opinions or tone that wasn’t present.
Example: Doctor says neutrally: “Your test results show elevated cholesterol.”
Interpreter says (with concerned tone): “Your cholesterol is dangerously high — you need to take this seriously!”
The interpreter added alarm that the doctor didn’t convey.
5. Role Confusion
What it is: Acting as advocate, advisor, or participant rather than neutral interpreter.
Examples:
- Answering questions for the patient without interpreting
- Giving medical advice
- Making decisions on behalf of the patient
- Having side conversations with one party
- Expressing personal opinions about treatment
⚠️ Professional interpreters are conduits for communication — not participants in it. The moment an interpreter starts giving opinions or making decisions, they’ve crossed an ethical line.
6. Medical Vocabulary Errors
What it is: Using incorrect medical terms or not knowing terminology.
Example: Doctor says “hypertension” — interpreter doesn’t know this means “high blood pressure” and uses a wrong or confusing term in ASL.
Why it’s dangerous: Patient may not understand their diagnosis, treatment, or instructions.
7. False Fluency
What it is: Appearing confident while actually not understanding.
Some interpreters don’t admit when they don’t understand something. They guess or make something up rather than asking for clarification.
What should happen: “I didn’t catch that term — could you explain what that means?” is appropriate and professional.
8. Cultural Errors
What it is: Missing cultural context that affects meaning.
Examples:
- Not recognizing that a patient’s “yes” is polite agreement rather than actual understanding
- Missing cultural beliefs about illness, treatment, or body
- Interpreting literally when a cultural idiom was used
- Not recognizing when a patient is uncomfortable discussing certain topics
9. Register Errors
What it is: Using inappropriate language level for the patient.
Example: Doctor uses technical terms. Interpreter uses equally technical ASL that the patient doesn’t understand (instead of interpreting in plain ASL).
The interpreter should match the register to the patient’s comprehension level, sometimes simplifying technical jargon.
10. Confidentiality Breaches
What it is: Sharing patient information outside the encounter.
Examples:
- Discussing patient cases with family or friends
- Recognizing a patient in public and mentioning the appointment
- Sharing information with the patient’s family without consent
This is both an ethical violation and potentially a HIPAA violation.
Why Do These Errors Happen?
| Root Cause | Related Errors |
|---|---|
| Insufficient training | All types — especially role confusion, vocabulary |
| Time pressure | Omissions, summarizing instead of interpreting |
| Lack of medical knowledge | Vocabulary errors, false fluency |
| Emotional involvement | Role confusion, additions, editorialization |
| Cultural factors | Substitutions (protecting patient), cultural errors |
| Fatigue | Omissions, vocabulary errors, overall quality decline |
How to Ensure Quality Medical Interpreting
For Healthcare Providers
- Use certified interpreters — RID certification or equivalent
- Use professional agencies — Not ad-hoc interpreters or family members
- Allow adequate time — Interpreted appointments take longer
- Speak directly to the patient — Not to the interpreter
- Use short sentences — Pause frequently for interpretation
- Check understanding — Ask the patient to repeat back key instructions
- Provide written materials — In the patient’s language when possible
Red Flags That Indicate Poor Interpreting
- Interpreter and patient having long exchanges that result in short interpretations
- Interpreter answering for the patient without interpreting
- Interpreter expressing personal opinions
- Interpreter seeming uncertain or confused
- Patient looks confused after interpretation
- Interpretation is much shorter or longer than original message
For Interpreting Agencies
- Credential verification — Confirm interpreter certifications
- Medical training — Provide ongoing medical terminology education
- Quality monitoring — Regular assessment and feedback
- Ethical standards — Clear policies on confidentiality and role boundaries
- Appropriate matching — Match interpreter skills to assignment complexity
Frequently Asked Questions
Should I use a family member to interpret?
No. Family members lack training, certification, and confidentiality obligations. They often omit embarrassing information, add opinions, and don’t know medical terminology. The ADA generally requires professional interpreters — not family members.
What if I notice interpreting errors?
Stop and address it. Ask for clarification. If the problem persists, request a different interpreter. Document concerns and report them to the interpreting agency. Patient safety comes first.
Are VRI interpreters less accurate than on-site?
Not necessarily. VRI uses the same professional interpreters. Quality depends on the interpreter’s skills, not the delivery method. However, VRI technical issues (poor video, connectivity) can cause problems. Ensure your equipment meets ADA standards.
How do I know if an interpreter is qualified?
Look for RID certification (for ASL) or CCHI/NBCMI certification (for spoken language medical interpreting). Ask about experience in healthcare settings. Work with reputable agencies that credential their interpreters.
Why Frederick Interpreting Agency?
Frederick Interpreting Agency prioritizes quality to minimize errors:
- Certified interpreters — RID certified or working toward certification
- Healthcare experience — Interpreters trained in medical terminology
- Deaf-owned — We understand effective communication from lived experience
- Ongoing training — Continuous professional development
- Quality standards — We hold our interpreters accountable
Request Qualified Medical Interpreters
On-site, VRI, or virtual — certified interpreters for healthcare settings.
Related Articles
- Hospital Video Remote Interpreting Guide
- How to Choose the Right Interpreting Service
- ADA Interpreter Requirements
Last updated: March 2026.
