Medical Abbreviations: 300 You Will See on a Chart

The dangerous abbreviations are not the rare ones. They are the pairs that look alike.

300 cardsLast updated 2026-08-31

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QD and QID differ by one letter and by three doses a day. MS means multiple sclerosis in a neurology note and something quite different on a medication list, which is why it sits on do-not-use lists. Charts are full of shorthand that is unambiguous to the person who wrote it and ambiguous to everyone else, and learning the pairs is more useful than learning the list. This deck is 300 cards, one abbreviation per card, written the way it appears on a chart. The back is cut into three fixed lines. "Stands for" gives the words the letters stand for. "Meaning" says in plain English what it refers to in practice. "Watch for" names the abbreviation it is confused with, or notes that it appears on a do-not-use list. The sections cover orders and routes, assessment and vital signs, laboratory and diagnostics, cardiovascular and respiratory, body systems and conditions, and word roots, prefixes and suffixes. No dose, rate or laboratory cut-off appears anywhere, because those depend on the patient and the local protocol and have no business being memorised from a card. Once the deck is on a spaced-repetition schedule, the abbreviations you read fluently stop coming back and the confusable pairs return until they stop being a hesitation.

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What's inside

Showing 100 representative cards from the full 300-card deck.

Front	Back
PRN	Stands for: Pro re nata. Meaning: As needed, rather than on a fixed schedule. Watch for: An order written this way must also state the indication and the minimum interval.
PC	Stands for: Post cibum. Meaning: After meals. Watch for: Confused with AC, and also with PC used for a personal computer in other notes.
BID	Stands for: Bis in die. Meaning: Twice a day. Watch for: Confused with TID, which is three times a day.
QID	Stands for: Quater in die. Meaning: Four times a day. Watch for: Frequently misread as QD, which means once daily.
QOD	Stands for: Quaque altera die. Meaning: Every other day. Watch for: On do-not-use lists because it is misread as QD or QID.
QAM	Stands for: Quaque ante meridiem. Meaning: Every morning. Watch for: Confused with QPM, which means every evening.
AM	Stands for: Ante meridiem. Meaning: Before noon, in the morning. Watch for: Used for timing rather than for dosing frequency.
PO	Stands for: Per os. Meaning: By mouth. Watch for: Confused with PR, which means rectally.
IV	Stands for: Intravenous. Meaning: Into a vein. Watch for: Confused with the Roman numeral four in handwritten notes.
SQ	Stands for: Subcutaneous. Meaning: Into the tissue just below the skin. Watch for: Also on do-not-use lists, and subcutaneous should be written out in full.
IT	Stands for: Intrathecal. Meaning: Into the space around the spinal cord. Watch for: A route with serious consequences if confused with intravenous.
NEB	Stands for: Nebuliser. Meaning: Given as a mist to be inhaled. Watch for: Different from an inhaler, which delivers a metered spray.
NGT	Stands for: Nasogastric tube. Meaning: A tube from the nose into the stomach. Watch for: Confused with NJ, which passes further into the jejunum.
OD	Stands for: Oculus dexter. Meaning: Right eye. Watch for: On do-not-use lists because it is also read as once daily and as overdose.
AD	Stands for: Auris dextra. Meaning: Right ear. Watch for: On do-not-use lists and confused with OD for right eye.
NPO	Stands for: Nil per os. Meaning: Nothing by mouth, including food, fluids and oral medicines. Watch for: An order that must state whether medicines are also withheld.
NAS	Stands for: No added salt. Meaning: A diet without salt added at the table or in cooking. Watch for: Not the same as a strictly sodium-restricted diet, which is more limited.
TPN	Stands for: Total parenteral nutrition. Meaning: Complete nutrition delivered into a vein. Watch for: Different from enteral nutrition, which uses the gastrointestinal tract.
BRP	Stands for: Bathroom privileges. Meaning: The patient may get up to use the bathroom. Watch for: More restrictive than up as tolerated and less than complete bed rest.
WBAT	Stands for: Weight bearing as tolerated. Meaning: The patient may put as much weight through the limb as comfort allows. Watch for: Different from partial weight bearing, which sets a limit.
VS	Stands for: Vital signs. Meaning: The set of basic physiological measurements recorded at each assessment. Watch for: The set recorded varies by setting, so the individual values must be checked.
HR	Stands for: Heart rate. Meaning: The number of heartbeats per minute. Watch for: Not always the same as the pulse rate, since some beats may not reach the periphery.
TPR	Stands for: Temperature, pulse and respiration. Meaning: A grouped record of three basic vital signs. Watch for: Blood pressure is not included, despite being a vital sign.
MAP	Stands for: Mean arterial pressure. Meaning: The average pressure in the arteries over a cardiac cycle. Watch for: Not the simple average of systolic and diastolic values.
HPI	Stands for: History of present illness. Meaning: The narrative account of the current problem. Watch for: Different from the past medical history, which covers earlier conditions.
PSH	Stands for: Past surgical history. Meaning: A record of previous operations. Watch for: Recorded separately from the medical history for clarity.
SH	Stands for: Social history. Meaning: Living situation, occupation, and habits such as smoking and alcohol use. Watch for: Also written for self-help in some contexts, so the section heading matters.
CC	Stands for: Chief complaint. Meaning: The main reason the patient sought care, ideally in their own words. Watch for: Also written for cubic centimetre, which is on do-not-use lists for volumes.
PE	Stands for: Physical examination. Meaning: The clinician's structured examination of the patient. Watch for: Also stands for pulmonary embolism, and the section of the note decides which is meant.
NAD	Stands for: No acute distress. Meaning: The patient appears comfortable at the time of assessment. Watch for: Also used for no abnormality detected, which is a different statement.
HEENT	Stands for: Head, eyes, ears, nose and throat. Meaning: A heading grouping the examination of those regions. Watch for: The neck is examined separately in most formats.
JVD	Stands for: Jugular venous distension. Meaning: Visible fullness of the neck veins. Watch for: Position affects the finding, so the angle of the bed should be recorded.
LOC	Stands for: Level of consciousness. Meaning: A description of how alert and responsive the patient is. Watch for: Also written for loss of consciousness, which is a different observation.
AVPU	Stands for: Alert, voice, pain, unresponsive. Meaning: A rapid scale for level of consciousness. Watch for: Simpler and less detailed than the Glasgow Coma Scale.
DTR	Stands for: Deep tendon reflex. Meaning: The reflex response elicited by tapping a tendon. Watch for: Graded on a scale, so the grade carries the meaning rather than present or absent.
MMSE	Stands for: Mini-Mental State Examination. Meaning: A brief structured test of cognitive function. Watch for: A screening tool rather than a diagnostic test.
NPI	Stands for: Numeric pain intensity. Meaning: A pain score reported by the patient on a numerical scale. Watch for: The scale used must be stated, since scales differ in range.
SOB	Stands for: Shortness of breath. Meaning: The subjective sensation of difficulty breathing. Watch for: Different from an abnormal respiratory rate, which is an observed sign.
LMP	Stands for: Last menstrual period. Meaning: The start date of the most recent menstrual period. Watch for: The first day is recorded, not the last.
CBC	Stands for: Complete blood count. Meaning: A panel measuring red cells, white cells and platelets. Watch for: A differential is a separate addition and is not always included.
Hgb	Stands for: Haemoglobin. Meaning: The oxygen-carrying protein in red cells. Watch for: Reported together with haematocrit, and the two move together but are not the same.
MCV	Stands for: Mean corpuscular volume. Meaning: The average size of a red blood cell. Watch for: Used to classify anaemia by cell size, not by cause.
RDW	Stands for: Red cell distribution width. Meaning: A measure of variation in red cell size. Watch for: A raised value indicates variation, not simply large or small cells.
BMP	Stands for: Basic metabolic panel. Meaning: A group of chemistry tests covering electrolytes, kidney function and glucose. Watch for: Narrower than the comprehensive panel, which adds liver tests.
Na	Stands for: Sodium. Meaning: The main electrolyte in extracellular fluid. Watch for: The measured value reflects the balance of sodium and water, not sodium alone.
BUN	Stands for: Blood urea nitrogen. Meaning: A waste product used to assess kidney function and hydration. Watch for: Affected by diet and bleeding, so it is interpreted with creatinine.
GFR	Stands for: Glomerular filtration rate. Meaning: A measure of how much blood the kidneys filter per minute. Watch for: Usually estimated from creatinine rather than measured directly.
Phos	Stands for: Phosphate. Meaning: A mineral involved in bone and energy metabolism. Watch for: Moves in the opposite direction to calcium in several conditions.
ALT	Stands for: Alanine aminotransferase. Meaning: An enzyme released when liver cells are damaged. Watch for: More specific to the liver than AST, which is also found in muscle.
Bili	Stands for: Bilirubin. Meaning: A breakdown product of haemoglobin processed by the liver. Watch for: Direct and indirect fractions point to different causes.
A1c	Stands for: Glycated haemoglobin. Meaning: A measure of average blood glucose over recent months. Watch for: Unreliable when red cell turnover is abnormal.
ABG	Stands for: Arterial blood gas. Meaning: A sample measuring oxygen, carbon dioxide and acid-base status. Watch for: Different from a venous sample, which cannot assess oxygenation the same way.
PaCO2	Stands for: Partial pressure of arterial carbon dioxide. Meaning: A measure reflecting how effectively the lungs clear carbon dioxide. Watch for: It reflects ventilation, while oxygen levels reflect gas exchange.
PT	Stands for: Prothrombin time. Meaning: A test of one arm of the clotting cascade. Watch for: Reported with the international normalised ratio for comparability.
PTT	Stands for: Partial thromboplastin time. Meaning: A test of a different arm of the clotting cascade. Watch for: Confused with prothrombin time, and the two assess different pathways.
UA	Stands for: Urinalysis. Meaning: A set of tests on a urine sample. Watch for: Also used for uric acid, so the context of the request matters.
C and S	Stands for: Culture and sensitivity. Meaning: Growing an organism and testing which agents inhibit it. Watch for: Sensitivity results take longer than the culture itself.
CXR	Stands for: Chest radiograph. Meaning: An X-ray image of the chest. Watch for: The view taken affects interpretation, so it is recorded with the result.
MRI	Stands for: Magnetic resonance imaging. Meaning: Imaging using a magnetic field rather than X-rays. Watch for: Metal implants may make it unsafe, so screening is required.
ECG	Stands for: Electrocardiogram. Meaning: A recording of the electrical activity of the heart. Watch for: Also abbreviated EKG, and both refer to the same test.
PFT	Stands for: Pulmonary function tests. Meaning: A set of tests measuring lung volumes and airflow. Watch for: Results depend on patient effort, so poor technique invalidates them.
MI	Stands for: Myocardial infarction. Meaning: Death of heart muscle from interrupted blood supply. Watch for: Confused with mitral insufficiency in older notes.
CHF	Stands for: Congestive heart failure. Meaning: Failure of the heart to pump adequately, causing fluid accumulation. Watch for: Now often written as heart failure, since congestion is not always present.
EF	Stands for: Ejection fraction. Meaning: The proportion of blood ejected from the ventricle with each beat. Watch for: It measures pumping efficiency, not the volume ejected.
AS in cardiology	Stands for: Aortic stenosis. Meaning: Narrowing of the aortic valve. Watch for: The same letters mean left ear in prescriptions, which is unrelated.
AF	Stands for: Atrial fibrillation. Meaning: An irregular rhythm arising from disorganised atrial activity. Watch for: Confused with atrial flutter, which is regular and has a different pattern.
PVC	Stands for: Premature ventricular contraction. Meaning: An early beat arising in the ventricle. Watch for: Also stands for a plastic used in tubing, so context matters.
AV block	Stands for: Atrioventricular block. Meaning: Delayed or blocked conduction between atria and ventricles. Watch for: The degree of block determines the significance, so the degree must be stated.
CABG	Stands for: Coronary artery bypass graft. Meaning: Surgery creating a new route around a blocked coronary artery. Watch for: Different from angioplasty, which opens the existing vessel.
ICD	Stands for: Implantable cardioverter defibrillator. Meaning: A device that detects and treats dangerous rhythms. Watch for: Also stands for the international classification of diseases in coding notes.
DVT	Stands for: Deep vein thrombosis. Meaning: A blood clot in a deep vein, usually of the leg. Watch for: Different from superficial thrombophlebitis, which affects surface veins.
COPD	Stands for: Chronic obstructive pulmonary disease. Meaning: Persistent airflow limitation, usually from long-term exposure to irritants. Watch for: Different from asthma, in which obstruction is largely reversible.
ARDS	Stands for: Acute respiratory distress syndrome. Meaning: Severe lung injury causing widespread inflammation and low oxygen. Watch for: Not simply severe pneumonia, and it has specific defining criteria.
ETT	Stands for: Endotracheal tube. Meaning: A tube placed in the trachea to secure the airway. Watch for: Different from a tracheostomy tube, which enters through the neck.
NC	Stands for: Nasal cannula. Meaning: A device delivering oxygen through short prongs in the nostrils. Watch for: It delivers a variable concentration that depends on the patient's own breathing.
CPAP	Stands for: Continuous positive airway pressure. Meaning: Constant pressure applied throughout the breathing cycle. Watch for: Different from bilevel support, which uses two pressure levels.
GI	Stands for: Gastrointestinal. Meaning: Relating to the digestive tract. Watch for: Upper and lower tract problems present differently, so the region should be stated.
GIB	Stands for: Gastrointestinal bleeding. Meaning: Blood loss from anywhere in the digestive tract. Watch for: Upper and lower sources produce different appearances of blood.
ARF	Stands for: Acute renal failure. Meaning: A rapid decline in kidney function. Watch for: Now more often written as acute kidney injury, which has defined criteria.
PD	Stands for: Peritoneal dialysis. Meaning: Dialysis using the peritoneal membrane as a filter. Watch for: Also stands for Parkinson disease, so context decides.
DM	Stands for: Diabetes mellitus. Meaning: A disorder of glucose regulation. Watch for: Distinct from diabetes insipidus, which concerns water balance.
HHS	Stands for: Hyperosmolar hyperglycaemic state. Meaning: Severe hyperglycaemia with dehydration and little ketosis. Watch for: Distinguished from ketoacidosis by the absence of significant acidosis.
Fx	Stands for: Fracture. Meaning: A break in a bone. Watch for: Confused with the abbreviation for family history in handwritten notes.
OA	Stands for: Osteoarthritis. Meaning: Degenerative joint disease from cartilage wear. Watch for: Distinct from rheumatoid arthritis, which is inflammatory and systemic.
SCI	Stands for: Spinal cord injury. Meaning: Damage to the spinal cord causing loss of function below the level. Watch for: The level and completeness both determine the consequences.
SDH	Stands for: Subdural haematoma. Meaning: A collection of blood beneath the dura. Watch for: Chronic and acute forms behave very differently.
OB	Stands for: Obstetrics. Meaning: The care of pregnancy and childbirth. Watch for: Also written for occult blood in laboratory notes.
SVD	Stands for: Spontaneous vaginal delivery. Meaning: Birth without instrumental or surgical assistance. Watch for: Different from assisted vaginal delivery.
NICU	Stands for: Neonatal intensive care unit. Meaning: A unit caring for critically ill newborns. Watch for: Different from the paediatric intensive care unit, which cares for older children.
cardi/o	Stands for: Heart. Meaning: The root used in terms relating to the heart. Watch for: Confused with cardia, which names the part of the stomach near the oesophagus.
gastr/o	Stands for: Stomach. Meaning: The root used in terms relating to the stomach. Watch for: Not the same as enter/o, which refers to the intestine.
my/o	Stands for: Muscle. Meaning: The root used in terms relating to muscle tissue. Watch for: Confused with myel/o, which means spinal cord or bone marrow.
derm/o and dermat/o	Stands for: Skin. Meaning: The roots used in terms relating to the skin. Watch for: Cutane/o is the Latin equivalent and appears in different terms.
a and an	Stands for: Without or absence of. Meaning: A prefix indicating that something is missing. Watch for: The form with the extra letter is used before a vowel.
brady	Stands for: Slow. Meaning: A prefix indicating a rate below normal. Watch for: The opposite of tachy, and the two are easily transposed.
epi	Stands for: Upon or above. Meaning: A prefix indicating a position on top of a structure. Watch for: Different from hyper, which indicates degree rather than position.
intra	Stands for: Within. Meaning: A prefix indicating a position inside a structure. Watch for: One letter separates it from inter, and the meanings are quite different.
itis	Stands for: Inflammation. Meaning: A suffix naming inflammation of a structure. Watch for: Inflammation is not always infection, so the two should not be equated.
otomy	Stands for: Incision. Meaning: A suffix naming an operation that cuts into a structure. Watch for: Different from ostomy, which leaves a permanent opening.
emia	Stands for: A blood condition. Meaning: A suffix naming the presence of something in the blood. Watch for: Different from uria, which refers to urine.

Frequently asked

What is in each section of the deck?

Orders and routes has 50 cards, assessment and vital signs 45, laboratory and diagnostics 55, cardiovascular and respiratory 55, body systems and conditions 55, and word roots, prefixes and suffixes 40, for 300 in total. Every card carries section and subtopic tags, so you can drill one area at a time.

Why are do-not-use abbreviations included?

Because you will still encounter them in older records and in handwriting, and recognising one is different from writing one. Where an abbreviation appears on such a list, the third line says so, so the card teaches you to read it without teaching you to use it.

Are any values or doses included?

None. No dose, no infusion rate and no laboratory reference range appears anywhere in the deck. Those vary by patient, by institution and over time, and looking them up in the current source is the correct habit. The deck covers what the letters mean and nothing more.

Can I import the whole deck on the free plan?

Yes. Importing a saved deck runs no new AI generation and spends no AI credits, so the free plan imports all 300 cards. You can study, edit and delete them afterwards.

Will importing it twice create duplicates?

No. Cards you already have are skipped and only cards added in a revision come through. Including re-imports after deleting it, one official deck can be imported three times per account.

Can I use it on the web and in the mobile app?

Yes. The deck is added to your account rather than to a device, so the same cards and the same progress are there on the web, on iOS and on Android.

Can I edit the cards after importing?

Yes. Imported cards are yours: you can edit both sides, delete cards you do not need, change tags, and move cards to another deck.