| Δ | change |
| ↓ | decrease |
| ↑ | increase |
| ↔ | to/from, in/out of |
| ∼ | approximate |
| = | equals |
| < | less than |
| > | greater than |
| # | number |
| − | minus |
| + | plus |
| & | and |
| etc | etcetera |
| % | percentage |
| ∥ | parallel bars |
| @ | each, at, before |
| ′ | foot |
| ″ | inch |
| ° | degree |
 | after |
| with |
| without |
| ♀ | female |
| ♂ | male |
| ¶ | paragraph |
| | |
| A | artery |
| a | ante (L) |
| A | assistance, assessment |
| AA | atlantoaxial; adjusted age; active assist |
| AAA | abdominal aortic aneurysm |
| AAO X3 | alert, awake, and oriented to date, person, place |
| ARRA | American Recovery Reinvestment Act |
| AAROM | active assisted range of motion |
| AARP | American Association of Retired Persons |
| Abd | abduction |
| ABG | arterial blood gases |
| AC | alternating current; acromioclavicular |
| a.c. | before a meal |
| ACA | anterior communicating artery; anterior cerebral artery |
| ACCE | academic coordinator of clinical education |
| ACL | anterior cruciate ligament |
| ACM | Arnold-Chiari malformation |
| ACSM | American College of Sports Medicine |
| AD | adduction, advanced directive, assistive device |
| ADA | American Dental Association, American Dietetics Association |
| ad lib | ad libitum (Latin), at pleasure |
| ADD | attention deficit disorder |
| ADHD | attention deficit hyperactivity disorder |
| ADL | activities of daily living |
| Adm | admitted |
| ADR | additional development required |
| AE(A) | above elbow amputation; preferred is transhumeral amputation |
| AF | atrial fibrillation, Arthritis Foundation |
| AFB | acid-fast bacillus |
| AFO | ankle foot orthosis |
| AFP | alpha-fetoprotein |
| AGA | appropriate for gestational age |
| AHA | American Heart Association, American Hospital Association |
| AHIMA | American Health Information Management Association |
| AI | aortic incompetence |
| AIDS | acquired immune deficiency syndrome |
| AIMS | Alberta infant motor scale |
| AK(A) | above knee amputation; preferred is transfemoral amputation |
| ALL | acute lymphocytic leukemia, anterior longitudinal ligament |
| ALJ | administrative law judge |
| ALS | amyotrophic lateral sclerosis; advanced life support |
| AM | morning |
| AMA | against medical advice; American Medical Association |
| amb. | ambulate, ambulation |
| AML | acute meylogenous leukemia, acute myelocytic leukemia |
| ANA | American Nursing Association |
| ANS | autonomic nervous system |
| ant. | anterior |
| AOTA | American Occupational Therapy Association |
| AP | anteroposterior, before dinner |
| APGAR | appearance, pulse, grimace, activity, respiration |
| APTA | American Physical Therapy Association |
| ARC | Association for Retarded Citizens |
| ARD | assessment reference dates |
| ARDS | adult respiratory distress syndrome |
| | acute respiratory distress syndrome |
| ARF | acute renal failure; acute respiratory failure |
| ARNP | Advanced Registered Nurse Practitioner |
| AROM | active range of motion |
| AS | aortic stenosis; ankylosing spondylitis |
| As & Bs | apnea and bradycardia |
| ASA | aspirin |
| ASAP | as soon as possible |
| ASD | atrial septal defect |
| ASHA | American Speech and Hearing Association |
| ASIS | anterior superior iliac spine |
| Asst, assist | assistance, assist |
| ATC | athletic trainer, certified |
| ATNR | asymmetric tonic neck reflex |
| AV | arteriovenous; atrioventricular; aortic valve |
| AVM | arteriovenous malformation |
| | |
| B | bilateral; both |
| BAER | brainstem auditory evoked response (hearing screening) |
| BBA | Balanced Budget Act |
| BBB | blood brain barrier; bundle-branch block |
| BCBS | Blue Cross and Blue Shield |
| BE | barium enema |
| BE(A) | below elbow amputation; preferred is transradial amputation |
| BIB | drink |
| BICU | burn intensive care unit |
| BID | bis in die (Latin); twice a day |
| Bil, bilat | bilateral |
| BIN | twice at night |
| BK(A) | below knee amputation; preferred is transtibial amputation |
| Bl | blood; bleeding |
| BM | bowel movement |
| BMI | body mass index |
| BMR | basal metabolic rate |
| BMT | bone marrow transplant |
| BOS | base of ... |