- Brown's tendon sheath syndrome 378.61
- Brown-Séquard's paralysis (syndrome) 344.89
- Brucella, brucellosis (infection) 023.9
- Bruck's disease 733.99
- Bruck-de Lange disease or syndrome (Amsterdam dwarf, intellectual disabilities, and brachycephaly) 759.89
- Brug's filariasis 125.1
- Brugada syndrome 746.89
- Brugsch's syndrome (acropachyderma) 757.39
- Bruhl's disease (splenic anemia with fever) 285.8
- Bruise (skin surface intact) - see also Contusion
- Bruit 785.9
- Brushburn - see Injury, superficial, by site
- Bruton's X-linked agammaglobulinemia 279.04
- Bruxism 306.8
- Bubbly lung syndrome 770.7
- Bubo 289.3
- Bubonic plague 020.0
- Bubonocele - see Hernia, inguinal
- Buccal - see condition
- Buchanan's disease (juvenile osteochondrosis of iliac crest) 732.1
- Buchem's syndrome (hyperostosis corticalis) 733.3
- Buchman's disease (osteochondrosis, juvenile) 732.1
