- T-shaped incisors 520.2
- Tab - see Tag
- Tabacism 989.84
- Tabacosis 989.84
- Tabardillo 080
- Tabes, tabetic
- Taboparalysis 094.1
- Taboparesis (remission) 094.1
- Tache noir 923.20
- Tachyalimentation 579.3
- Tachyarrhythmia, tachyrhythmia - see also Tachycardia
- Tachycardia 785.0
- Tachygastria 536.8
- Tachypnea 786.06
- Taenia (infection) (infestation) (see also Infestation, taenia) 123.3
- Taeniasis (intestine) (see also Infestation, taenia) 123.3
- Taenzer's disease 757.4
- Tag (hypertrophied skin) (infected) 701.9
- Tahyna fever 062.5
- Takayasu (-Onishi) disease or syndrome (pulseless disease) 446.7
- Takotsubo syndrome 429.83
- Talc granuloma 728.82