- Treponema pallidum infection (see also Syphilis) 097.9
- Treponematosis 102.9
- Triad
- Trichiasis 704.2
- Trichinella spiralis (infection) (infestation) 124
- Trichinelliasis 124
- Trichinellosis 124
- Trichiniasis 124
- Trichinosis 124
- Trichobezoar 938
- Trichocephaliasis 127.3
- Trichocephalosis 127.3
- Trichocephalus infestation 127.3
- Trichoclasis 704.2
- Trichoepithelioma (M8100/0) - see also Neoplasm, skin, benign
- Trichofolliculoma (M8101/0) - see Neoplasm, skin, benign
- Tricholemmoma (M8102/0) - see Neoplasm, skin, benign
- Trichomatosis 704.2
- Trichomoniasis 131.9
- Trichomycosis 039.0
- Trichonocardiosis (axillaris) (palmellina) 039.0
- Trichonodosis 704.2
