- (CAIS)
- 1,4-Butanediol
- 12-Year-Old Boy
- 1st Table East
- 1st Table North
- 21-Hydroxylase
- 221B Baker Street
- 24 connections
- 2nd Chief Surgeon
- 2nd ER Doctor
- 2nd Table East
- 2nd Table West
- 5-alpha-reductase inhibitor
- 5 to 9
- 9-1-1
- 97 Seconds
- A.J. Trauth
- ACE
- ACE inhibitor
- ACTH
- ACTH stimulation test
- ADAMTS13
- ADHD
- AIDS
- AMA
- ARDS
- ATP
- AVN
- AZT
- A Pox on Our House
- Aaron Himelstein
- Aaron Refvem
- Aasha Davis
- Abbey
- Abbey McBride
- Abby Morgenthal
- Abby Nash
- Abdomen
- Abdominal distension
- Abdominal epilepsy
- Abdominoplasty
- Abducens nerve
- Abigail Ralphean
- Ablation
- Abnormal posturing
- Abortion
- Aboulia
- Abscess
- Abulia
- Acamprosate
- Acanthocyte
- Acanthosis
- Acanthosis nigricans
- Acceptance
- Accessory nerve
- Acetaminophen
- Acetazolamide
- Acetone
- Acetylcholine
- Acetylcholinesterase inhibitor
- Acetylcysteine
- Achalasia
- Achilles tendon
- Achy-Breaky QB
- Aciclovir
- Acid reflux
- Acidosis
- Acinetobacter baumannii
- Acne
- Acoustic neuroma
- Acromegaly
- Acrophobia
- Act Your Age
- Actaea racemosa
- Actin
- Actinium
- Activated charcoal
- Acupuncture
- Acute
- Acute fatty liver of pregnancy
- Acute myeloid leukemia
- Acute promyelocytic leukemia
- Adair Tishler
- Adam (Distractions)
- Adam (Fidelity)
- Adam (disambiguation)
- Adam Brown
- Adam Busch
- Adam Cagley
- Adam Garcia
- Adam Kelvey
- Adam Rothenberg
- Adam Trahan
- Adderall
- Addiction
- Addie
- Addison's Disease
- Adele Brown
- Adele Robbins
- Adenocarcinoma
- Adenoma
- Adenosine
- Adenosine triphosphate
- Adenovirus
- Adhesive capsulitis of shoulder
- Adina Porter
- Adipose capsule of kidney
- Administrator
- Admitting Nurse Colleen
- Adrenal crisis
- Adrenal gland
- Adrenaline
- Adrenergic agonist
- Adrenocortical carcenoma
- Adrenocortical carcinoma
- Adrenoleukodystrophy
- Adrian LaTourelle
- Adrienne Janic
- Adrienne Maldonado
- Adult Refsum disease
- Adverse Events
- Aflatoxin
- African Slave
- African trypanosomiasis
- Afsoun Hamidi
- After Hours
- Agar plate
- Agent Boss
- Agglutination
- Agnes
- Agnosia
- Agoraphobia
- Agraphia
- Aikoa Tanaka
- Aimee Bell
- Ainsley Barton
- Airborne
- Aisha Kabia
- Akanni Ayo
- Akiko Morison
- Akinetopsia
- Al Coronel
- Al Espinosa
- Al Foster
- Alan Alston
- Alan Frazier
- Alan Mueting
- Alan Rosenberg
- Alana Husband
- Alanine transaminase
- Alanna Ubach
- Albendazole
- Albert Malafronte
- Albert Owens
- Albinism
- Albumin
- Alcohol
- Alcoholics Anonymous
- Alcoholism
- Aldosterone
- Alec George
- Alejandro Patino
- Aleksandra Wojda
- Alex (assistant)
- Alex (student)
- Alex Alexander
- Alex Desert
- Alex Fernandez
- Alex Quijano
- Alex Schemmer
- Alex Skuby
- Alex Sol
- Alex Weed
- Alexander disease
- Alexandra Barreto
- Alexandra Bokyun Chun
- Alexandra Lydon
- Alexandria Robinson
- Alexia
- Alexie Gilmore
- Alexis Raben
- Alexis Thorpe
- Alfredo
- Ali
- Ali Damji
- Alice Hartman
- Alice Lo
- Alice Tanner
- Alice in Wonderland syndrome
- Alicia Foreman
- Alien hand syndrome
- Alix Korey
- Alkaline phosphatase
- Alkalosis
- Alkylating antineoplastic agent
- All In
- Allan Rich
- Allele
- Allen
- Allergy
- Allex Macormick
- Allison Cameron
- Allison Ochmanek
- Allison Smith
- Alone
- Alpha 1-antitrypsin
- Alpha 1-antitrypsin deficiency
- Alpha wave
- Alport syndrome
- Alprazolam
- Alternative medicine
- Aluminum
- Alveolar rhabdomyosarcoma
- Alyson Morgan
- Alyson Stoner
- Alyssa Shafer
- Alzheimer's disease
- Ama
- Amanda Foreman
- Amanda Leighton
- Amanda Seyfried
- Amantadine
- Amber's Apartment
- Amber (case history)
- Amber DeMarco
- Amber Matthews
- Amber Tamblyn
- Amber Volakis
- Amber hallucination
- Ambulance
- Ambulance Driver
- Ambulance driver
- Ameoba
- America Olivo
- Americium
- Amino acid
- Amir Ramos
- Ammonia
- Amnesia
- Amniotic fluid
- Amniotic sac
- Amobarbital
- Amoeba
- Amoebiasis
- Amoebic parasitoma
- Amoxicillin
- Amphetamine
- Amphetamine Overdose
- Amphotericin
- Amphotericin B
- Ampicillin
- Ampulla of Vater
- Amputation
- Amrinone
- Amsacrine
- Amy
- Amy (Words and Deeds)
- Amy (disambiguation)
- Amy (doll)
- Amy Arrington
- Amy Davidson
- Amy Dudgeon
- Amy Hadley
- Amy Irving
- Amy Landecker
- Amygdala
- Amylase
- Amyloidosis
- Amyotrophic lateral sclerosis
- Ana Lenchantin
- Ana Lucasey
- Anabolic steroid
- Anabolic steroid abuse
- Anaerobic glycolysis
- Anagrelide
- Anakinra
- Anandamide
- Anaphylaxis
- Anaplastic carcinoma
- Anasarca
- Anastrozole
- Anatomy
- Anconeus muscle
- Andi Eystad
- Andie
- Andray Johnson
- Andre
- Andre Braugher
- Andre M. Johnson
- Andrea Bendewald
- Andrea Gabriel
- Andres Tavares
- Andrew Airlie
- Andrew Bernstein
- Andrew Borba
- Andrew Fiscella
- Andrew Keegan
- Andrew Leeds
- Androgen insensitivity syndrome
- Andrology
- Andropause
- Andy Comeau
- Andy Milder
- Andy Scott Harris
- Anemia
- Anesha Ndiaye
- Anesthesiologist (Babies & Bathwater)
- Anesthesiologist (Detox)
- Anesthesiologist (Distractions)
- Anesthesiologist (Sleeping Dogs Lie)
- Anesthetic
- Aneurysm
- Angel Oquendo
- Angela Bettis
- Angela Gots
- Angela Whitney
- Angelyna Martinez
- Angie
- Angina
- Angiodysplasia
- Angioedema
- Angiogenesis inhibitor
- Angiogram
- Angiokeratoma
- Angioplasty
- Angle
- Anhedonia
- Anica Jovanovich
- Anisocoria
- Anita
- Anke
- Ankylosing spondylitis
- Ann Dowd
- Anna
- Anna Drumm
- Anna Khaja
- Annabelle Attanasio
- Anne
- Anne Ayala
- Anne Dudek
- Anne Elizabeth Ramsay
- Anne Hadley
- Anne Ling
- Annette M. Lesure
- Annette Raines