Medical abbreviations
What bid, prn, CBC and the rest mean, in English and Spanish.
Most of these come from prescriptions, lab orders and discharge papers. One abbreviation can mean two things, so if you aren’t sure, ask the clinician to say the full words.
No matches. Try a shorter word.
Prescriptions and dosing
Short Latin forms from prescriptions and discharge papers. If a clinician reads one out loud, ask for the plain words.
- bid
- Twice a day
- dos veces al día
- tid
- Three times a day
- tres veces al día
- qid
- Four times a day
- cuatro veces al día
- qhs
- Every night at bedtime
- todas las noches al acostarse
- Easy to misread as qhr (every hour).
- prn
- As needed
- cuando lo necesite
- po
- By mouth
- por la boca, por vía oral
- NPO
- Nothing by mouth
- nada por la boca, en ayunas
- Ask if that means no food, no drink or both, and from when.
- ac
- Before meals
- antes de las comidas
- pc
- After meals
- después de las comidas
- q4h
- Every 4 hours
- cada 4 horas
- The number changes. q6h is every 6 hours.
- stat
- Right away
- de inmediato
- SL
- Under the tongue
- debajo de la lengua, sublingual
- gtt
- Drops
- gotas
- tab
- Tablet
- tableta, pastilla
- cap
- Capsule
- cápsula
- mg
- Milligram
- miligramo
- mL
- Milliliter
- mililitro
- OTC
- Over the counter
- sin receta, de venta libre
- Rx
- Prescription
- receta
Tests, imaging and lab terms
Knowing the test name does not tell you the result. Keep numbers and units exactly as said.
- ABG
- Arterial blood gases
- gasometría arterial
- CBC
- Complete blood count
- conteo sanguíneo completo, hemograma
- In Mexico, biometría hemática (BH).
- CRP
- C-reactive protein
- proteína C reactiva (PCR)
- In Spanish, PCR can also mean a PCR test.
- CXR
- Chest x-ray
- radiografía de tórax
- ECG / EKG
- Electrocardiogram
- electrocardiograma (ECG)
- EEG
- Electroencephalogram
- electroencefalograma (EEG)
- GFR
- Glomerular filtration rate
- tasa de filtración glomerular (TFG)
- HCT
- Hematocrit
- hematocrito
- HGB
- Hemoglobin
- hemoglobina
- HDL
- High-density lipoprotein
- colesterol HDL
- LDL
- Low-density lipoprotein
- colesterol LDL
- MRI
- Magnetic resonance imaging
- resonancia magnética
- RBC
- Red blood cell
- glóbulo rojo
- WBC
- White blood cell
- glóbulo blanco
Conditions and infections
“Checking for,” “history of” and “diagnosed with” mean different things. Keep the one the speaker used.
- AFIB
- Atrial fibrillation
- fibrilación auricular
- CAD
- Coronary artery disease
- enfermedad de las arterias coronarias
- CHF
- Congestive heart failure
- insuficiencia cardíaca congestiva
- COPD
- Chronic obstructive pulmonary disease
- enfermedad pulmonar obstructiva crónica (EPOC)
- DM
- Diabetes mellitus
- diabetes
- DVT
- Deep-vein thrombosis
- trombosis venosa profunda
- GERD
- Gastroesophageal reflux disease
- reflujo gastroesofágico
- HTN
- Hypertension
- hipertensión, presión alta
- IBD
- Inflammatory bowel disease
- enfermedad inflamatoria intestinal
- IBS
- Irritable bowel syndrome
- síndrome del intestino irritable
- MI
- Myocardial infarction
- infarto de miocardio, ataque al corazón
- MRSA
- Methicillin-resistant Staphylococcus aureus
- estafilococo resistente a la meticilina
- URI
- Upper respiratory infection
- infección de las vías respiratorias altas
- UTI
- Urinary tract infection
- infección urinaria
- In parts of Latin America, UTI also means intensive care (unidad de terapia intensiva).
Care settings, measurements and routes
A route or allergy label is not a full instruction. Ask about anything missing.
- BP
- Blood pressure
- presión arterial
- Also tensión arterial.
- BMI
- Body mass index
- índice de masa corporal (IMC)
- CPR
- Cardiopulmonary resuscitation
- reanimación cardiopulmonar (RCP)
- ENT
- Ear, nose and throat
- otorrinolaringología
- Patients say “el otorrino.”
- ICU
- Intensive care unit
- unidad de cuidados intensivos, terapia intensiva
- IM
- Intramuscular
- intramuscular
- IV
- Intravenous
- intravenoso
- Patients often call an IV drip suero.
- NKDA
- No known drug allergies
- sin alergias conocidas a medicamentos
Banned and easy to misread
The Joint Commission bans some abbreviations in medication orders because people misread them: U and IU (units), QD and QOD (daily, every other day), and MS, MSO4 and MgSO4 (morphine or magnesium sulfate). If you hear or see one, ask for the full word.
Two traps for Spanish: “once” means eleven in Spanish, so never use it for “once a day.” Say “una vez al día.” And in Mexico, “cada tercer día” means every other day, not every third day.
Joint Commission guidance · ISMP list of error-prone abbreviations (PDF)
What would you say?
A note says “CA.” Which meaning is it?
You can't tell. MedlinePlus lists both cancer and calcium for CA. Ask: “For the interpreter, what does CA stand for here?” Don't pick one from context.
The doctor says, “We will repeat the CBC tomorrow.” What do you say?
CBC is a complete blood count. Say the test name and nothing more. Don't add a result or a reason. If you don't know the Spanish term, ask for clarification instead of guessing.
A medication order says “MS.” Is it morphine?
Maybe, maybe not. MS can mean morphine sulfate or magnesium sulfate, so the Joint Commission bans it in orders and medication-related documentation. Ask the clinician to say the full name of the medicine.
Where the meanings come from
Meanings follow MedlinePlus where it lists them, and the common U.S. prescription meanings for the rest. Spanish names of conditions and tests follow MedlinePlus en español. Checked October 8, 2026. Notes are ours. Your agency’s glossary comes first.
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