What does BID mean in medical terms?

BID means twice daily (from Latin bis in die). It is used on prescriptions and in clinical notes to indicate a medication or treatment should be given two times per day, often morning and evening.

What does NPO mean in medical terms?

NPO means nothing by mouth (nil per os). Patients are kept NPO before surgery or certain procedures to reduce the risk of aspiration. Food and drink are withheld for a specified period.

What does PRN mean on a prescription?

PRN means as needed (pro re nata). It indicates that a medication or treatment should be given only when necessary, not on a fixed schedule. Common for pain relievers, anti-nausea drugs, and sleep aids.

What do PO, IV, and IM mean in medicine?

PO means by mouth (per os, oral). IV means intravenous (into a vein). IM means intramuscular (into muscle). These abbreviations specify the route of administration for medications.

What does CBC mean in lab work?

CBC stands for complete blood count. It includes hemoglobin, white blood count (WBC), red blood count (RBC), platelets, and often hematocrit and other indices. It is one of the most common blood tests ordered.

Medical Abbreviation Dictionary

Look up common medical abbreviations used in prescriptions, clinical notes, and healthcare documentation. Search by abbreviation or meaning. This reference includes terms for vitals, routes of administration (PO, IV, IM), frequency (BID, TID, PRN), labs (CBC, BMP, GFR), and common conditions. For educational and reference use only; not a substitute for professional medical advice.

195 terms

Vitals & assessment

BP: Blood pressure. Often written as systolic/diastolic (e.g. 120/80 mmHg).
HR: Heart rate. Measured in beats per minute (bpm).
RR: Respiratory rate. Breaths per minute.
Temp: Temperature. Body temperature, usually in °C or °F.
SpO2: Oxygen saturation. Percentage of hemoglobin saturated with oxygen (pulse oximetry).
BMI: Body mass index. Weight (kg) / height (m)²; used to categorize underweight, normal, overweight, obesity.
BSA: Body surface area. Used for drug dosing and metabolic calculations.
MAP: Mean arterial pressure. Average pressure in arteries during a cardiac cycle.
O2: Oxygen. Often used for oxygen therapy or saturation.
FiO2: Fraction of inspired oxygen. Concentration of oxygen in inspired air (e.g. 0.21 room air).

Route of administration

PO: Per os (by mouth). Oral administration.
IV: Intravenous. Given into a vein.
IM: Intramuscular. Injected into muscle.
SC: Subcutaneous. Injected under the skin.
PR: Per rectum. Rectal administration.
SL: Sublingual. Under the tongue.
IN: Intranasal. Via the nose.
TOP: Topical. Applied to the skin or surface.
IVPB: IV piggyback. Small-volume IV medication given via secondary line.
NG: Nasogastric. Via tube through nose into stomach.
ET: Endotracheal. Via endotracheal tube (e.g. for resuscitation).

Frequency

QD: Once daily. One time per day (prefer “once daily” in writing to avoid confusion with QOD).
BID: Twice daily. Two times per day (e.g. morning and evening).
TID: Three times daily.
QID: Four times daily.
QOD: Every other day.
PRN: As needed. When necessary, not on a fixed schedule.
STAT: Immediately. At once.
QHS: At bedtime. From Latin quaque hora somni.
AC: Before meals (ante cibum).
PC: After meals (post cibum).
Q4H: Every 4 hours.
Q6H: Every 6 hours.
Q8H: Every 8 hours.
Q12H: Every 12 hours (twice daily).
QAM: Every morning.
QPM: Every evening.
QW: Once weekly.

General

Rx: Prescription or treatment. Symbol for “recipe” or “take”.
NPO: Nothing by mouth (nil per os). Patient should not eat or drink, e.g. before surgery or procedures.
Dx: Diagnosis.
Hx: History (e.g. medical history, family history).
Tx: Treatment or therapy.
Sx: Symptoms or surgery (context-dependent).
Fx: Fracture.
C/O: Complaining of. Chief complaint.
WD: Well developed. Often in physical exam documentation.
NAD: No acute distress.
SOB: Shortness of breath.
DOE: Dyspnea on exertion. Shortness of breath with activity.
LOC: Level of consciousness. Alert, drowsy, unresponsive, etc.
A&O: Alert and oriented. Often A&Ox3 (person, place, time) or A&Ox4.
WNL: Within normal limits.
HEENT: Head, eyes, ears, nose, throat. Common exam section.
CV: Cardiovascular. Heart and circulation.
Lungs: Lungs / respiratory. Often “lungs CTA” (clear to auscultation).
CTA: Clear to auscultation. No abnormal breath sounds.
Abd: Abdomen. Abdominal exam.
Ext: Extremities. Arms and legs.
Neuro: Neurological. Nervous system exam.
MSK: Musculoskeletal.
Skin: Skin. Integumentary exam.
LMP: Last menstrual period. Used in OB and gynecology.
EDC: Estimated date of confinement. Due date (pregnancy).
GA: Gestational age. Weeks of pregnancy.
Gravida: Number of pregnancies. Often written as G2P1 (gravida 2, para 1).
Para: Number of deliveries (parity).
ROM: Range of motion; or rupture of membranes (OB context).
EBL: Estimated blood loss. Used in surgery and delivery.
NKA: No known allergies. Same idea as NKDA.
FHx: Family history.
Meds: Medications. Current medication list.
CC: Chief complaint. Main reason for visit.
HPI: History of present illness. Narrative of current complaint.
PE (exam): Physical exam. Full physical examination (distinct from PE = pulmonary embolism).
A/P: Assessment and plan. Summary and treatment plan.
f/u: Follow-up. Follow-up visit or plan.
PCP: Primary care physician (or provider).
D/C: Discharge or discontinue (context-dependent).
OTC: Over the counter. Non-prescription medication.
R/O: Rule out. Working diagnosis to be confirmed or excluded.
ROS: Review of systems. Systematic symptom review.
PMH: Past medical history.
FH: Family history.
SH: Social history.
NKDA: No known drug allergies.
ADL: Activities of daily living.
DNR: Do not resuscitate. No CPR or advanced life support.
CPR: Cardiopulmonary resuscitation.
ED: Emergency department.
OR: Operating room.
PACU: Post-anesthesia care unit. Recovery after surgery.
ICU: Intensive care unit.
NICU: Neonatal intensive care unit.

Labs

CBC: Complete blood count. Includes hemoglobin, WBC, RBC, platelets.
BMP: Basic metabolic panel. Electrolytes, kidney function, glucose.
CMP: Comprehensive metabolic panel. BMP plus liver enzymes, albumin, bilirubin.
LFT: Liver function tests. ALT, AST, bilirubin, alkaline phosphatase, etc.
Hb: Hemoglobin. Often in g/dL.
Hgb: Hemoglobin. Same as Hb.
WBC: White blood count. Leukocytes; can indicate infection or inflammation.
RBC: Red blood count. Erythrocytes.
PLT: Platelets. Thrombocytes; important for clotting.
PT: Prothrombin time. Coagulation test; often reported with INR.
INR: International normalized ratio. Standardized measure of anticoagulation (e.g. warfarin).
HbA1c: Glycated hemoglobin. Reflects average blood glucose over ~3 months; used in diabetes monitoring.
BUN: Blood urea nitrogen. Kidney function marker.
Cr: Creatinine. Kidney function; used in GFR equations.
GFR: Glomerular filtration rate. Estimate of kidney function.
Na: Sodium. Serum sodium (electrolyte).
K: Potassium. Serum potassium (electrolyte).
Ca: Calcium. Serum calcium.
Cl: Chloride. Serum chloride (electrolyte).
HCO3: Bicarbonate. Serum bicarbonate (electrolyte, acid-base).
ALT: Alanine aminotransferase. Liver enzyme.
AST: Aspartate aminotransferase. Liver enzyme.
ALP: Alkaline phosphatase. Liver/bone enzyme.
TBil: Total bilirubin. Liver function marker.
Alb: Albumin. Serum protein; liver and nutrition marker.
Gluc: Glucose. Blood sugar.
TSH: Thyroid-stimulating hormone. Thyroid function test.
T4: Thyroxine. Thyroid hormone.
LDL: Low-density lipoprotein. “Bad” cholesterol.
HDL: High-density lipoprotein. “Good” cholesterol.
TG: Triglycerides. Lipid panel component.
Hct: Hematocrit. Percentage of blood volume that is red cells.
MCV: Mean corpuscular volume. Average red blood cell size.
ESR: Erythrocyte sedimentation rate. Nonspecific inflammation marker.
CRP: C-reactive protein. Inflammation marker.
PTT: Partial thromboplastin time. Coagulation test.
aPTT: Activated partial thromboplastin time. Coagulation test.
UA: Urinalysis. Urine test.
ABG: Arterial blood gas. Measures pH, PaO2, PaCO2, bicarbonate.
PaO2: Partial pressure of oxygen (arterial). From ABG.
PaCO2: Partial pressure of carbon dioxide (arterial). From ABG.

Conditions

HTN: Hypertension. High blood pressure.
CHF: Congestive heart failure. Heart failure with fluid overload.
MI: Myocardial infarction. Heart attack.
STEMI: ST-elevation myocardial infarction. Type of heart attack with ST elevation on ECG.
NSTEMI: Non-ST-elevation myocardial infarction. Heart attack without ST elevation.
AF: Atrial fibrillation. Irregular heart rhythm.
AFib: Atrial fibrillation. Same as AF.
DVT: Deep vein thrombosis. Blood clot in deep veins (e.g. leg).
PE: Pulmonary embolism. Blood clot in pulmonary arteries.
DM: Diabetes mellitus. Often DM1 (type 1) or DM2 (type 2).
COPD: Chronic obstructive pulmonary disease. Emphysema, chronic bronchitis.
GERD: Gastroesophageal reflux disease. Acid reflux.
UTI: Urinary tract infection.
CVA: Cerebrovascular accident. Stroke.
TIA: Transient ischemic attack. “Mini-stroke”; temporary neurologic deficit.
CAD: Coronary artery disease.
CKD: Chronic kidney disease.
ARDS: Acute respiratory distress syndrome. Severe lung injury.
DKA: Diabetic ketoacidosis. Acute complication of diabetes.
GI: Gastrointestinal.
GU: Genitourinary.
PNA: Pneumonia. Lung infection.
URI: Upper respiratory infection. Common cold, pharyngitis, etc.
LRI: Lower respiratory infection. Bronchitis, pneumonia.
IBD: Inflammatory bowel disease. Crohn’s, ulcerative colitis.
IBS: Irritable bowel syndrome.
PUD: Peptic ulcer disease. Stomach or duodenal ulcer.
DM1: Diabetes mellitus type 1. Insulin-dependent diabetes.
DM2: Diabetes mellitus type 2. Often non–insulin-dependent.
RA: Rheumatoid arthritis. Autoimmune joint disease.
OA: Osteoarthritis. Degenerative joint disease.
SLE: Systemic lupus erythematosus. Autoimmune disease.
HIV: Human immunodeficiency virus.
AIDS: Acquired immunodeficiency syndrome.
TB: Tuberculosis.
BPH: Benign prostatic hyperplasia. Enlarged prostate.
PID: Pelvic inflammatory disease.
GAD: Generalized anxiety disorder.
MDD: Major depressive disorder.
PTSD: Post-traumatic stress disorder.
ADHD: Attention-deficit/hyperactivity disorder.
OSA: Obstructive sleep apnea.
N/V: Nausea and vomiting.

Imaging & procedures

ECG: Electrocardiogram. Heart rhythm and electrical activity (EKG is same).
EKG: Electrocardiogram. Same as ECG.
CT: Computed tomography. CT scan.
MRI: Magnetic resonance imaging.
X-ray: Radiograph. Plain film imaging.
US: Ultrasound. Sonography.
CXR: Chest X-ray. Chest radiograph.
KUB: Kidneys, ureters, bladder. Plain abdominal X-ray.
MRA: Magnetic resonance angiography. MRI of blood vessels.
CTA: CT angiography. CT scan with contrast for vessels (distinct from CTA = clear to auscultation).
PET: Positron emission tomography. Nuclear imaging.
EEG: Electroencephalogram. Brain electrical activity.
EMG: Electromyography. Muscle and nerve electrical studies.
Echo: Echocardiogram. Ultrasound of the heart.
LP: Lumbar puncture. Spinal tap.
Cath: Catheterization. Often cardiac catheterization.
C-section: Cesarean section. Surgical delivery.