- Beer-drinkers' heart (disease) 425.5
- Begbie's disease (exophthalmic goiter) 242.0
- Behavior disorder, disturbance - see also Disturbance, conduct
- Behçet's syndrome 136.1
- Behr's disease 362.50
- Beigel's disease or morbus (white piedra) 111.2
- Bejel 104.0
- Bekhterev's disease (ankylosing spondylitis) 720.0
- Bekhterev-Strümpell-Marie syndrome (ankylosing spondylitis) 720.0
- Belching (see also Eructation) 787.3
- Bell's
- Bence-Jones albuminuria, albuminosuria, or proteinuria 791.0
- Bends 993.3
- Benedikt's syndrome (paralysis) 344.89
- Benign - see also condition
- Bennett's
- Benson's disease 379.22
- Bent
- Bereavement V62.82
- Berger's paresthesia (lower limb) 782.0
- Bergeron's disease (hysteroepilepsy) 300.11
- Beriberi (acute) (atrophic) (chronic) (dry) (subacute) (wet) 265.0