# List of medical abbreviations: A

Sortable table :
| Abbreviation | Meaning |
| ā | (a with a bar over it) before (from Latin ante) before |
| A | assessment |
| a.a. | of each (from Latin ana ana) amino acids: A or Ala – alanine C or Cys – cysteine D or Asp – aspartic acid E or Glu – glutamic acid F or Phe – phenylalanine H or His – histidine I or Ile – isoleucine K or Lys – lysine L or Leu – leucine M or Met – methionine N or Asn – asparagine O or Pyl – pyrrolysine P or Pro – proline Q or Gln – glutamine R or Arg – arginine S or Ser – serine T or Thr – threonine U or Sec – selenocysteine V or Val – valine W or Trp – tryptophan Y or Tyr – tyrosine |
| A1C | glycated hemoglobin (hemoglobin A1c) |
| Aa. | arteria, see Artery |
| Aag | abdominal aortic aneurysm (pronounced "triple-A") |
| AAD | antibiotic-associated diarrhea |
| AAI | acute arterial insufficiency |
| AAPMC | antibiotic-associated pseudomembranous colitis |
| AAT | activity as tolerated atypical antibody test |
| AAL | anterior axillary line |
| AAOx3 | awake, alert, and oriented, times 3 (i.e., to person, place, and time) |
| AAOx4 | awake, alert, and oriented, times 3 (i.e., to person, place, time, and event) |
| A/B | acid-base ratio |
| ab | abdomen, abdominal abortion |
| Ab | antibody |
| AB | abortion, AB (blood type) |
| ABC | airway, breathing, circulation aspiration biopsy cytology |
| ABCD | airway, breathing, circulation, disability asymmetry, borders, color, diameter (features on considering "Is it a malignant melanoma?") ABCD rating (a staging system for prostate cancer) |
| ABCs ABCDs ABCDEs | airway, breathing, circulation, etc. Refers to priority of needs in emergency situations. Exact spell-out and details after "C" vary by institution, but the "ABCs" theme is recurrent. |
| Abd | abdomen abdominal[abduction] |
| ABD | [abdominal |
| ABE | acute bacterial endocarditis |
| ABG | arterial blood gas |
| ABI | acquired brain injury ankle brachial pressure index |
| ABLA | acute blood loss anemia |
| ABMT | autologous bone marrow transplantation |
| Abn | abnormal |
| ABO | Landsteiner's blood grouping system |
| ABPA | allergic broncho-pulmonary aspergillosis |
| ABPI | ankle brachial pressure index |
| ABR | Auditory Brainstem Response |
| ABT | antibiotic therapy |
| ABVD | Doxorubicin (adriamycin), bleomycin, vinblastine, dacarbazine (first-line treatment for Hodgkin's lymphoma) |
| ABX | antibiotics |
| a.c. AC | before a meal (from Latin ante cibum) |
| AC | abdominal circumference assisted controlled ventilation acromioclavicular joint antecubital fossa |
| ACA | acinic cell carcinoma Affordable Care Act anterior cerebral artery |
| ACB | aortocoronary bypass |
| AC&BC | air conduction and bone conduction, as in Weber test |
| Acc | accommodation (eye) |
| ACCU | acute coronary care unit |
| ACD | anemia of chronic disease |
| ACD | allergic contact dermatitis |
| ACDF | anterior cervical discectomy and fusion |
| Ace | acetone |
| ACE | angiotensin-converting enzyme |
| ACEI | angiotensin-converting enzyme inhibitor(s) |
| ACh | acetylcholine |
| AChE | acetylcholine esterase |
| ACL | anterior cruciate ligament |
| ACLS | advanced cardiac life support |
| ACS | altered conscious state acute coronary syndrome acute chest syndrome |
| ACM | arrhythmogenic cardiomyopathy |
| ACTH | adrenocorticotropic hormone |
| ACP | advance care planning Advanced Clinical Practitioner |
| ACPO | acute colonic pseudo-obstruction |
| ACU | ambulatory care unit |
| ad. | right ear (from Latin auris dexter) |
| AD | Alzheimer's disease acute distress aortic dissection right ear (from Latin auris dexter) as directed |
| ADA | adenosine deaminase American Dental Association American Diabetes Association; e.g., "ADA diet" Americans with Disabilities Act |
| ADC | AIDS dementia complex |
| ADCC | antibody-dependent cell-mediated cytotoxicity |
| ADD | attention deficit disorder |
| ADE | adverse drug event |
| ADH | antidiuretic hormone |
| ADHD | attention deficit hyperactivity disorder |
| ADHF | acute decompensated heart failure |
| ADHR | autosomal dominant hypophosphatemic rickets |
| ADLs | activities of daily living |
| ad lib | as desired (from Latin ad libitum) |
| adm | admission |
| Adn | adnexa (for example, adnexa of the uterus) |
| ADP | adenosine diphosphate |
| ad part. dolent | to the painful parts (from Latin ad partes dolentes) |
| ADR | adverse drug reaction |
| ADW | Ain't Doin' Well |
| A/E | Air entry |
| A+E | accident and emergency |
| AEB | as evidenced by (commonly used by nurses) |
| AED | automated external defibrillator antiepileptic drug(s) |
| AEM | ambulatory electrocardiogram monitoring |
| AF | atrial fibrillation atrial flutter amniotic fluid |
| AF-AFP | amniotic fluid alpha fetoprotein |
| AFB | acid-fast bacilli |
| AFI | amniotic fluid index |
| AFib | atrial fibrillation |
| AFL | atrial flutter |
| AFNTR | acute febrile nonhemolytic transfusion reaction |
| AFO | ankle-foot orthosis |
| AFP | alpha-fetoprotein |
| AFSOF | anterior fontanelle soft, open, flat |
| Ag | antigen |
| AGA | anti-gliadin antibodies appropriate gestational age (see birth weight) |
| AGC | atypical glandular cells |
| AGES criteria | age, grade, extent, size (for tumors) |
| AGN | acute glomerulonephritis |
| AH | auditory hallucinations |
| a.h. | every other hour (from Latin alternis horis) |
| AHD | arteriosclerotic heart disease |
| AHF | antihemophilic factor |
| AHG | antihemophilic globulin |
| AHH | aryl hydrocarbon hydroxylase |
| AHI | Apnea-Hypopnea Index |
| AHR | airway hyper-reactivity |
| AHT | antihyaluronic acid test |
| AI | artificial insemination aortic insufficiency aromatase inhibitors |
| AICD | automated implantable cardioverter-defibrillator |
| AID | artificial insemination by donor |
| AIDS | acquired immune deficiency syndrome |
| AIH | artificial insemination by husband |
| AIHA | autoimmune hemolytic anemia |
| AIHD | artificial insemination by pooled husband and donor semen |
| AIPD | acute infectious and parasitical diseases autoimmune progesterone dermatitis acute inflammatory demyelinating polyneuropathy |
| AIIRB | angiotensin II receptor antagonist |
| AIN | allergic interstitial nephritis |
| AIR | anterior interval release acute inpatient rehabilitation |
| AIS | adenocarcinoma in situ androgen insensitivity syndrome |
| AJCC | American Joint Committee on Cancer |
| AjD | adjustment disorder |
| AK | acanthamoeba keratitis |
| aka | also known as |
| AKA | above-knee amputation also known as |
| AKI | acute kidney injury, previously called Acute Renal Failure (ARF) |
| ALA | aminolevulinic acid |
| ALCAPA | anomalous left coronary artery from the pulmonary artery |
| ALF | assisted living facility |
| ALG | antilymphocytic globulin |
| ALI | acute limb injury acute lung injury |
| Alk phos | alkaline phosphatase (sometimes abbreviated as ALP) |
| ALL | acute lymphoblastic leukemia allergies |
| ALP | alkaline phosphatase (sometimes abbreviated as Alk phos) |
| ALPS | autoimmune lymphoproliferative syndrome |
| ALS | amyotrophic lateral sclerosis, also known as motor neurone disease ('MND), Lou Gehrig's disease or Charcot disease advanced life support |
| ALT | alanine transaminase |
| ALTE | apparent life-threatening event |
| altern. d. | every other day (from Latin alterno die) |
| AMA | advanced maternal age (often defined as 35 years or greater) against medical advice antimitochondrial antibody American Medical Association |
| Amb | ambulate |
| AMC | arthrogryposis multiplex congenita |
| AMI | acute mesenteric ischemia acute myocardial infarction |
| AML | acute myeloid leukemia |
| AMO | advanced medical optics |
| AMP | adenosine monophosphate |
| Amp | ampule ampere |
| AMPA receptor | alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor of the brain |
| AMS | acute mountain sickness atypical measles syndrome altered mental status |
| Amt | amount |
| ANA | antinuclear antibody |
| ANCA | antineutrophil cytoplasmic antibody |
| AND | allowing natural death |
| ANDI | aberrations of normal development and involution (of breast) |
| ANF | atrial natriuretic factor |
| ANP | atrial natriuretic peptide |
| ANS | autonomic nervous system |
| Ant | anterior |
| Anti- | refers to an antibody to the suffixed antigen |
| ANTR | asymmetrical tonic neck reflex |
| ANUG | acute necrotizing ulcerative gingivitis |
| A&O or A/O | aware and oriented or alert and oriented |
| A&Ox3 | alert and oriented, times 3 (to person, place, and time) |
| A&Ox4 | alert and oriented, times 4 (to person, place, time, and circumstances) (often used interchangeably with A&Ox3) |
| AODM | adult-onset diabetes mellitus (now called diabetes mellitus type 2) |
| AOM | acute otitis media |
| AOE | acute otitis externa |
| a.p. | before a meal (from Latin ante prandium) |
| AP | action potential alkaline phosphatase angina pectoris anteroposterior apical area postrema |
| A&P | auscultation and percussion anatomy and physiology |
| A/P | anatomy and physiology assessment and plan |
| APACHE II | Acute Physiology and Chronic Health Evaluation II |
| APAP | paracetamol (aka acetaminophen) (from its chemical name, N-acetyl-para-aminophenol) automatic positive airway pressure |
| APC | atrial premature contraction antigen-presenting cell activated protein C argon plasma coagulation |
| APD | adult polycystic disease automated peritoneal dialysis |
| APKD | adult polycystic kidney disease |
| APECED | autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy |
| APGAR | appearance, pulse, grimace, activity, respiration (used to assess newborns) |
| APH | antepartum haemorrhage |
| APLS | antiphospholipid syndrome |
| APMPPE | acute posterior multifocal placoid pigment epitheliopathy |
| applic. | applicandus (Latin meaning "to be applied") |
| appy | appendectomy |
| APP | as per protocol (e.g., per institutional clinical protocol or per scientific protocol) |
| APR | abdominoperineal resection |
| APS | autoimmune polyendocrine/polyglandular syndrome antiphospholipid syndrome |
| APSAC | anisoylated plasminogen streptokinase activator complex |
| aPTT | activated partial thromboplastin time |
| aq. | water (from Latin aqua) |
| aq. bull. | boiling water (from Latin aqua bulliens) |
| aq. calid. | warm or hot water (from Latin aqua calida) |
| aq. dist. | distilled water (from Latin aqua distillata) |
| aq. gel. | cold water (from Latin aqua gelida) |
| AR | aortic regurgitation attributable risk |
| ARB | angiotensin II receptor antagonist |
| ARBI | alcohol-related brain injury (such as a fetal alcohol spectrum disorder or alcohol-related dementia) |
| ARC | AIDS-related complex |
| ARD | absolute risk difference alcohol-related dementia |
| ARDS | acute respiratory distress syndrome |
| ARF | acute renal failure |
| ARFID | avoidant/restrictive food intake disorder |
| Arg | arginine |
| ARM | artificial rupture of membranes (also abbreviated as AROM) |
| ARMD | age-related macular degeneration |
| ARMS | alveolar rhabdomyosarcoma |
| AROM | active range of motion artificial rupture of membranes |
| ART | antiretroviral therapy assuming room temperature (that is, the patient has died) assisted reproductive technology |
| ARVC | arrhythmogenic right ventricular cardiomyopathy |
| ARVD | arrhythmogenic right ventricular dysplasia |
| AS | aortic stenosis atherosclerosis ankylosing spondylitis |
| ASA | acetylsalicylic acid (aspirin) American Society of Anesthesiologists (physical status class) |
| ASB | asymptomatic bacteriuria |
| ASC | ambulatory surgery center atypical squamous cells |
| ASCA | anti–Saccharomyces cerevisiae antibodies |
| ASC-H | atypical squamous cells—cannot exclude HSIL |
| ASCAD | arteriosclerotic coronary artery disease |
| ASCUS ASC-US | atypical squamous cells of undetermined significance |
| ASCVD | arteriosclerotic vascular disease (arteriosclerosis) |
| ASD | atrial septal defect autism spectrum disorder |
| ASGUS | atypical squamous glandular cells of undetermined significance |
| ASH ASHD | arteriosclerotic heart disease (coronary heart disease) |
| ASH | asymmetric septal hypertrophy alcoholic steatohepatitis |
| ASIS | anterior superior iliac spine |
| ASM | anti-seizure medication (anticonvulsant) |
| ASO | antistreptolysin-O |
| ASOT | antistreptolysin-O titre |
| ASPECTS | Alberta Stroke Program Early CT Score, ASPECT Score |
| Ass | assessment |
| AST | aspartate transaminase |
| ASX | asymptomatic |
| A-T | ataxia-telangiectasia |
| AT | antithrombin angiotensin |
| AT-III | antithrombin III |
| ATA | antitransglutaminase antibodies |
| ATB | antibiotic |
| ATCC | ATCC (company) (formerly the American Type Culture Collection) |
| ATCP | atypical chest pain |
| ATG | anti-thymocyte globulin |
| ATLS | Advanced trauma life support |
| ATN | acute tubular necrosis |
| ATNR | asymmetrical tonic neck reflex |
| ATP | acute thrombocytopenic purpura adenosine triphosphate antitachycardia pacing |
| Atp | atypical |
| ATRA | all-trans retinoic acid |
| ATS | antitetanus serum, that is, antitetanus immunoglobulins |
| AU | each ear (from Latin auris utraque) |
| AUC | area under the curve (pharmacology) |
| aur. | ear (from Latin auris) |
| aur. dextro. | to right ear (from Latin auris dextrae) |
| aur. laev | to left ear (from Latin auris laevae) |
| aurist. | ear drops (from Latin auristillae) |
| AUS | Artificial urinary sphincter |
| AV | arteriovenous atrioventricular |
| AVF | arteriovenous fistula |
| AVM | arteriovenous malformation |
| AVN | avascular necrosis atrioventricular node |
| AVR | aortic valve replacement |
| AVSD | atrioventricular septal defect |
| afebrile, vital signs stable |
| A&W A/W | alive and well associated with admitted with |
| Ax | axillary |
| AXR | abdominal x-ray |
| AYA | adolescents and young adults |
| AZT | azidothymidine |