AB
- Abnormal excessive sweating (See: Hyperhidrosis)
- Abruptio placentae (See: Placental abruption)
- Abusive head trauma; Shaken impact syndrome; Inflicted head injury; Whiplash shaken infant syndrome(See:Shaken baby syndrome, abusive head trauma)
AC
- Acute lymphoblastic leukemia (See: Acute lymphocytic leukemia)
- Acute lymphoid leukemia (See: Acute lymphocytic leukemia)
- Acute myeloblastic leukemia (See: Acute myelogenous leukemia)
- Acute myeloid leukemia (See: Acute myelogenous leukemia)
- Acute nonlymphocytic leukemia (See: Acute myelogenous leukemia)
AD
- Adenitis, mesenteric (See: Mesenteric lymphadenitis)
- Adnexal mass (See: Adnexal tumor)
AI
- AIDP, Acute inflammatory demyelinating polyneuropathy (See: Guillain-Barre syndrome)
- AIDS; Acquired immunodeficiency syndrome; human immunodeficiency virus (See: HIV)
- Airplane ear (See: Ear barotrauma)
AL
- Alopecia (See: Hair loss)
AN
- Anal cancer
- Anal itching
- Anemia, iron deficiency (See: Iron deficiency anemia)
- Anemia, vitamin deficiency (See: Vitamin deficiency anemia)
- Aneurysm (See: Popliteal artery aneurysm)
- Aneurysm, brain (See: Brain aneurysm)
- Aneurysm, cerebral (See: Brain aneurysm)
- Aneurysm, thoracic (See: Thoracic aortic aneurysm)
- Angioedema and hives (See: Hives and angioedema)
- Ankle (See: Ankle fracture)
- Ankle Arthritis, Foot (See: Foot and Ankle Arthritis)
- Ankyloglossia (See: Tongue-tie)
- Anterior cruciate ligament injury (See: ACL injury)
- Antibiotic-associated colitis (See: Pseudomembranous colitis)
AO
- Aortic coarctation (See: Coarctation of the aorta)
- Aortic valve regurgitation
AP
- Aphthous ulcer (See: Canker sore)
- Apical ballooning syndrome (See: Broken heart syndrome)
AR
- ARDS (See: Acute respiratory distress syndrome)
- Arrhythmia (See: Heart arrhythmia)
- Arteriosclerosis (See: Atherosclerosis)
- Arteritis, giant cell (See: Giant cell arteritis)
- Arteritis, Takayasu's (See: Takayasu's arteritis)
- Arthritis, basal joint; Arthritis (See: Thumb arthritis)
- Arthritis, degenerative (See: Osteoarthritis)
- Arthritis, gouty (See: Gouty arthritis)
- Arthritis, reactive (See: Reactive arthritis)
- Arthritis, rheumatoid (See: Rheumatoid arthritis)
- Arthritis, septic (See: Septic arthritis)
A
- Arthritis, psoriatic (See: Psoriatic arthritis)
AS
- ASD (See: Atrial Septal Defect)
- Aseptic necrosis (See: Avascular necrosis)
- Asthma, childhood (See: Childhood asthma)
AT
- Atrial fibrillation
- Atrial tachycardia
- Atrioventricular canal defect
- Atrioventricular nodal reentry tachycardia (AVNRT)
- Atrophic vaginitis (See: Vaginal atrophy)
- Atypical moles (See: Dysplastic nevus)
AV
- AVN (See: Avascular necrosis (osteonecrosis))
- AVNRT (See: Atrioventricular nodal reentry tachycardia)
