Common Medical Abbreviations Comprehensive Guide
![]() |
Common Medical Abbreviations |
Medical abbreviations are widely used in prescriptions, medical records, and patient instructions to ensure efficient communication between healthcare professionals. Understanding these abbreviations is crucial for pharmacists, nurses, and doctors to prevent medication errors and ensure patient safety.
1. Prescription Filling Directions
These abbreviations are commonly used when prescribing and dispensing medications.
Abbreviation |
Meaning |
aa |
Of each |
ad |
Up to; to
make |
disp. |
Dispense |
div. |
Divide |
d.t.d. |
Give of such
doses |
ft. |
Make |
M. |
Mix |
No. |
Number |
non rep. |
Do not repeat |
q.s. |
A sufficient
quantity |
Sig |
Write
(directions on the label) |
📌 Example Usage:
- Rx: Amoxicillin 500 mg Sig: 1 tab q8h for 7 days.
- Translation: Take one tablet every 8 hours for 7 days.
2. Quantities and Measurement Abbreviations
These abbreviations refer to units of measurement used in prescriptions.
Abbreviation |
Meaning |
BSA |
Body surface
area |
cm³ |
Cubic
centimeter |
f or fl (fluidus) |
Fluid |
g |
Gram |
gal |
Gallon |
gtt (gutta) |
Drop |
lb (libra) |
Pound |
kg |
Kilogram |
L |
Liter |
m² or M² |
Square meter |
mcg |
Microgram |
mEq |
Milliequivalent |
mg |
Milligram |
mg/kg |
Milligrams
per kilogram of body weight |
mg/m² |
Milligrams
per square meter of body surface area |
mL |
Milliliter |
mL/h |
Milliliters
per hour (for IV administration) |
oz. |
Ounce |
O. or pt. |
Pint |
qt. |
Quart |
ss or ss (semissem) |
One-half |
tbsp. |
Tablespoonful |
tsp. |
Teaspoonful |
📌 Example Usage:
- Rx: Furosemide 40 mg Sig: 1 tab po qAM
- Translation: Take one tablet by mouth every morning.
3. Patient Instructions Abbreviations
These abbreviations guide how and when to take medications.
Abbreviation |
Meaning |
a.c. |
Before meals |
ad lib. |
At pleasure,
freely |
admin |
Administer |
A.M. |
Morning |
aq. (aqua) |
Water |
ATC |
Around the
clock |
b.d. or
b.i.d. |
Twice a day |
c or c̅ |
With |
d (die) |
Day |
dil. |
Dilute |
et |
And |
h. or hr. |
Hour |
h.s. |
At bedtime |
i.c. |
Between meals |
min. |
Minute |
m&n |
Morning and
night |
N&V |
Nausea and
vomiting |
H.S. |
Night |
NPO |
Nothing by
mouth |
p.c. |
After meals |
P.M. |
Afternoon;
evening |
p.o. |
By mouth
(orally) |
p.r.n. |
As needed |
q |
Every |
qAM |
Every morning |
q4h, q8h,
etc. |
Every __
hours |
qd or QD |
Once a day,
every day |
q.i.d. |
Four times a
day |
rep. |
Repeat |
s or s̅ |
Without |
o.d. |
Once a day |
s.o.s. |
If needed; as
necessary |
stat. |
Immediately |
t.i.d. |
Three times a
day |
wk. |
Week |
📌 Example Usage:
- Rx: Metformin 500 mg Sig: 1 tab p.c. b.i.d.
- Translation: Take one tablet after meals twice a day.
4. Importance of Medical Abbreviations
✅ Improves Efficiency
- Abbreviations save time when writing prescriptions and medical notes.
✅ Ensures Clear Communication
- Standard abbreviations help pharmacists, nurses, and doctors understand prescriptions accurately.
⚠️ Risks of Misinterpretation
- Some abbreviations, like qd (once daily) and q.i.d. (four times daily), can be confused, leading to medication errors.
- Solution: Use capital letters and clear handwriting or switch to electronic prescriptions.
5. Commonly Confused Medical Abbreviations
Incorrect Abbreviation |
Potential Error |
Safer Alternative |
U (Unit) |
Mistaken as
"0" or "4", leading to overdose |
Write
"Unit" |
IU
(International Unit) |
Confused with
"IV" (intravenous) |
Write
"International Unit" |
q.d. (every
day) |
Mistaken as
"q.i.d." (four times daily) |
Write
"daily" |
MS (Morphine
Sulfate) |
Confused with
Magnesium Sulfate (MgSO₄) |
Write
"Morphine Sulfate" |
cc (cubic
centimeter) |
Can be
mistaken for "u" (units) |
Write
"mL" |
6. Tips for Safe Use of Medical Abbreviations
🔹 Use standard abbreviations – Avoid non-standard shortcuts that may be misunderstood.
🔹 Confirm dosage and frequency – If unclear, clarify with the prescribing doctor.
🔹 Educate patients – Explain what each abbreviation means on their prescription.
🔹 Utilize electronic prescribing systems – Reduces errors due to handwriting misinterpretation.
🔹 Cross-check prescriptions – Pharmacists should verify unclear abbreviations before dispensing medications.
Conclusion
Medical abbreviations streamline prescription writing and medical documentation, but they must be used correctly to avoid misinterpretation and medication errors. Healthcare professionals should always adhere to standard abbreviations and educate patients on their prescribed medication regimens.
What are medical abbreviations?
Medical abbreviations are shortened forms of words or phrases used by healthcare professionals to communicate efficiently, save time, and ensure consistency in medical records, prescriptions, and patient instructions.
Why are medical abbreviations used?
Medical abbreviations are used to increase efficiency in the healthcare setting by simplifying communication, especially for healthcare providers working in fast-paced environments.
What does "a.c." stand for in medical terms?
"a.c." stands for "ante cibum", meaning "before meals."
What is the meaning of "b.i.d."?
"b.i.d." stands for "bis in die", meaning "twice a day."
What does "p.o." refer to?
"p.o." stands for "per os", meaning "by mouth" or "orally."
What does "NPO" mean in a medical setting?
"NPO" stands for "Nil Per Os", meaning "nothing by mouth." This is used when a patient should refrain from eating or drinking before surgery or a medical test.
What is the difference between "q.d." and "q.i.d."?
q.d. (quaque die) means "once daily". q.i.d. (quater in die) means "four times a day."
What does "t.i.d." mean in medication instructions?
"t.i.d." stands for "ter in die", meaning "three times a day."
What is the meaning of "PRN" in a prescription?
"PRN" stands for "pro re nata", meaning "as needed." This is often used for medications taken based on symptoms, such as painkillers.
What does "stat." mean on a prescription or order?
"Stat." means "immediately", indicating that the medication or procedure should be carried out without delay.
What does "q4h" mean in medical instructions?
"q4h" means "every 4 hours". It's used to specify that a medication should be administered every four hours.
What does "b.d." or "bd" stand for?
"b.d." (or "bd") stands for "bis die", meaning "twice a day." It is commonly used for prescribing medications taken two times per day.
What is the meaning of "a.m." and "p.m." in medical prescriptions?
a.m. refers to the morning time, typically from midnight to noon. p.m. refers to the afternoon or evening, typically from noon to midnight.
What does "q.i.d." mean?
"q.i.d." stands for "quater in die", which means "four times a day."
What is meant by "disp." on a prescription?
"Disp." stands for "dispense", meaning to give or provide the prescribed medication.
What does "h.s." mean in medical instructions?
"h.s." stands for "hora somni", meaning "at bedtime." It indicates that a medication should be taken before going to sleep.
What does "dil." mean in a medical prescription?
"dil." stands for "dilute", meaning to add a solvent (like water or saline) to a substance to reduce its concentration.
What is the meaning of "gtt" in a prescription?
"gtt" stands for "gutta", which means "drop." This is commonly used for liquid medications.
What does "s.o.s." mean in medical prescriptions?
"s.o.s." stands for "si opus sit", meaning "if there is need" or "as needed." It is often used for medications that can be taken when required, like pain relievers.
Why should I understand medical abbreviations in prescriptions?
Understanding medical abbreviations ensures accurate interpretation of prescription instructions, reducing the chances of errors and improving patient safety. Always seek clarification if unsure about an abbreviation used in a prescription.