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