China 
Africa 
- Arthritis mutilans
- Arthrocentesis
- Arthrodesis
- Arthrodial
- Arthrofibrosis
- Arthrogram
- Arthrography
- Arthrogryposis
- Arthropathy
- Arthroplasty
- Arthroscopic lavage
- Arthroscopic surgery
- Arthroscopy
- Arthrospira
- Arthrotomy
- Arthus reaction
- Articaine
- Artichokes
- Articular capsule
- Articular cartilage
- Articular cartilage repair
- Articular disc
- Articular disk
- Articular processes
- Articular surface
- Articular tubercle
- Articulation Index
- Articulators
- Articulatory suppression
- Artificial blood
- Artificial bone
- Artificial cells
- Artificial cerebrospinal fluid
- Artificial chromosome
- Artificial gravity
- Artificial heart
- Artificial heart valve
- Artificial hybridization
- Artificial immune system
- Artificial insemination
- Artificial intelligence
- Artificial kidney
- Artificial ligaments
- Artificial limbs
- Artificial liver
- Artificial membranes
- Artificial muscles
- Artificial neural networks
- Artificial organs
- Artificial ovary
- Artificial pancreas
- Artificial pneumothorax
- Artificial rupture of membranes
- Artificial selection
- Artificial skin
- Artificial sweeteners
- Artificial tears
- Artificial transcription factors
- Artificial urinary sphincter
- Artificial vaginas
- Artificial womb
- Aryepiglottic fold
- Aryepiglottic muscle
- Aryl hydrocarbon receptor
- Aryl hydrocarbon receptor nuclear translocator
- Aryl sulfotransferase
- Arylalkylamines
- Arylamidase
- Arylamine N-acetyltransferase
- Arylation
- Arylcyclohexylamines
- Arylesterase
- Arylsulfatase
- Arylsulfatase B
- Arytenoid adduction
- Arytenoid cartilage
- Arytenoid muscle
- Arzoxifene
- Asafoetida
- Asbestos
- Asbestosis
- Ascariasis
- Ascaridia
- Ascaridia galli
- Ascaris
- Ascaris lumbricoides
- Ascaris suum
- Ascending aorta
- Ascending cervical artery
- Ascending cholangitis
- Ascending colon
- Ascending palatine artery
- Ascending pharyngeal artery
- Ascending reticular activating system
- Ascertainment bias
- Asciminib
- Ascites
- Ascl1
- Ascomycin
- Ascorbate peroxidase
- Ascorbic acid
- Ascorbic acid deficiency
- Ascorbyl palmitate
- Ascoviridae
- Asenapine
- Asepsis
- Aseptic meningitis
- Aseptic necrosis
- Aseptic technique
- Asexual reproduction
- Asexuality
- Asfarviridae
- Asfotase alfa
- Ash
- Asherman's syndrome
- Asialoglycoprotein
- Asialoglycoprotein receptor
- Asomatognosia
- Asoprisnil
- Aspalathus linearis
- Asparaginase
- Asparagine
- Asparagine synthetase
- Asparagus
- Asparagus officinalis
- Aspartame
- Aspartate
- Aspartate aminotransferase
- Aspartate protease
- Aspartate semialdehyde dehydrogenase
- Aspartate transaminase
- Aspartic acid
- Aspartic proteases
- Aspartic proteinase
- Aspartoacylase
- Asperger syndrome
- Aspergilloma
- Aspergillosis
- Aspergillus
- Aspergillus clavatus
- Aspergillus fumigatus
- Aspergillus niger
- Asperlicin
- Aspermia
- Asphyxia
- Asphyxiant gases
- Asphyxiating thoracic dysplasia
- Aspidosperma quebracho-blanco
- Aspiration
- Aspiration pneumonia