- Basic anxiety
- Basic fibroblast growth factor
- Basic helix-loop-helix
- Basic helix–loop–helix
- Basic life support
- Basic metabolic panel
- Basic reproduction number
- Basic rest-activity cycle
- Basicranium
- Basidiobolomycosis
- Basidiobolus
- Basigin
- Basilar artery
- Basilar invagination
- Basilar membrane
- Basilar plexus
- Basilar skull fracture
- Basilic vein
- Basiliximab
- Basioccipital
- Basivertebral veins
- Basket cells
- Basolateral amygdala
- Basolateral membrane
- Basopenia
- Basophil activation
- Basophilia
- Basophilic stippling
- Basophils
- Basti
- Bath salts
- Bathocuproine
- Batimastat
- Batrachotoxin
- Batroxobin
- Batson venous plexus
- Batten disease
- Battered child syndrome
- Battered woman
- Battle's sign
- Battlemind
- Baumann's angle
- Baux score
- Baxdela
- Bayes factor
- Bayesian approach
- Bayesian inference
- Bayesian learning
- Bayesian method
- Bayesian networks
- Bayesian statistics
- Bayley Scales of Infant Development
- Baylisascaris
- Baylisascaris procyonis
- Bazedoxifene
- Bcl-2
- Bcl-2 family
- Bcl-2 homologous antagonist killer
- Bcl-2-associated X protein
- Bcl-2-associated death promoter
- Bcl-xL
- Bcl-xl
- Bcl10
- Bcl11a
- Bcr-Abl tyrosine-kinase inhibitors
- Bcr-abl tyrosine-kinase inhibitors
- Bdellovibrio
- Beals syndrome
- Beam balance
- Beam's eye view
- Bean
- Beard
- Beau's lines
- Beauveria bassiana
- Beauvericin
- Becaplermin
- Beck Anxiety Inventory
- Beck Depression Inventory
- Beck Hopelessness Scale
- Beck's triad
- Becker muscular dystrophy
- Becker nevus
- Becker's muscular dystrophy
- Becker's nevus
- Beckwith-Wiedemann Syndrome
- Beckwith-Wiedemann syndrome
- Beclabuvir
- Beclin 1
- Beclometasone
- Beclometasone dipropionate
- Becquerel
- Bed
- Bed bug infestation
- Bed bugs
- Bed rest
- Bed sharing
- Bed-making
- Bedaquiline
- Bedridden
- Bedwetting
- Bee pollen
- Bee venom
- Beer's law
- Beer-Lambert law
- Beers Criteria
- Beeswax
- Beet sugar
- Beets
- Beevor's sign
- Behavior
- Behavior Rating Inventory of Executive Function
- Behavior analyst
- Behavior change
- Behavior change techniques
- Behavior genetics
- Behavior management
- Behavior modification
- Behavior therapy
- Behavioral Observation Audiometry
- Behavioral activation
- Behavioral addiction
- Behavioral change
- Behavioral disinhibition
- Behavioral disorders
- Behavioral immune system
- Behavioral inhibition
- Behavioral medicine
- Behavioral modification
- Behavioral momentum
- Behavioral neurology
- Behavioral parent training
- Behavioral plasticity
- Behavioral psychology
- Behavioral script
- Behavioral therapy
- Behavioral treatment
- Behaviorally anchored rating scales
- Behaviorism
- Behaviour therapy
- Behavioural change theories
- Behavioural design
- Behavioural genetics
- Behavioural synchrony
- Behcet's disease
- Behcet's syndrome
- Behenic acid
- Behentrimonium chloride
- Behrens-Fisher problem
- Bejel
- Belantamab mafodotin