- Terminal care V66.7
- Termination
- Ternidens diminutus infestation 127.7
- Terrors, night (child) 307.46
- Terry's syndrome (see also Retinopathy of prematurity) 362.21
- Tertiary - see condition
- Tessellated fundus, retina (tigroid) 362.89
- Test(s)
- Testicle, testicular, testis - see also condition
- Tetanus, tetanic (cephalic) (convulsions) 037
- Tetany, tetanic 781.7
- Tetralogy of Fallot 745.2
- Tetraplegia - see Quadriplegia
- Thailand hemorrhagic fever 065.4
- Thalassanemia 282.49
- Thalassemia (alpha) (beta) (disease) (Hb-C) (Hb-D) (Hb-E) (Hb-H) (Hb-I) (high fetal gene) (high fetal hemoglobin) (intermedia) (major) (minima) (minor) (mixed) (trait) (with other hemoglobinopathy) 282.49
- Thalassemic variants 282.49
- Thaysen-Gee disease (nontropical sprue) 579.0
- Thecoma (M8600/0) 220
- Thelarche, precocious 259.1
- Thelitis 611.0
- Therapeutic - see condition
