- Brailsford's disease 732.3
- Brailsford-Morquio disease or syndrome (mucopolysaccharidosis IV) 277.5
- Brain - see also condition
- Branched-chain amino-acid disease 270.3
- Branchial - see condition
- Brandt's syndrome (acrodermatitis enteropathica) 686.8
- Brash (water) 787.1
- Brass-founders' ague 985.8
- Bravais-Jacksonian epilepsy (see also Epilepsy) 345.5
- Braxton Hicks contractions 644.1
- Braziers' disease 985.8
- Brazilian
- BRBPR (bright red blood per rectum) 569.3
- Break
- Breakbone fever 061
- Breakdown
- Breast - see condition
- Breast feeding difficulties 676.8
- Breath
- Breathing
- Breathlessness 786.09
- Breda's disease (see also Yaws) 102.9
