- Breast feeding difficulties 676.8
- Breath
- Breathing
- Breathlessness 786.09
- Breda's disease (see also Yaws) 102.9
- Breech
- Breisky's disease (kraurosis vulvae) 624.09
- Brennemann's syndrome (acute mesenteric lymphadenitis) 289.2
- Brenner's
- Bretonneau's disease (diphtheritic malignant angina) 032.0
- Breus' mole 631.8
- Brevicollis 756.16
- Bricklayers' itch 692.89
- Brickmakers' anemia 126.9
- Bridge
- Bright red blood per rectum (BRBPR) 569.3
- Bright's
- Brill's disease (recrudescent typhus) 081.1
- Brill-Symmers disease (follicular lymphoma) (M9690/3) 202.0
- Brill-Zinsser disease (recrudescent typhus) 081.1
- Brinton's disease (linitis plastica) (M8142/3) 151.9
- Brion-Kayser disease (see also Fever, paratyphoid) 002.9