- Thorson-Biörck syndrome (malignant carcinoid) 259.2
- Threadworm (infection) (infestation) 127.4
- Threatened
- Three-day fever 066.0
- Threshers' lung 495.0
- Thrix annulata (congenital) 757.4
- Throat - see condition
- Thrombasthenia (Glanzmann's) (hemorrhagic) (hereditary) 287.1
- Thromboangiitis 443.1
- Thromboarteritis - see Arteritis
- Thromboasthenia (Glanzmann's) (hemorrhagic) (hereditary) 287.1
- Thrombocytasthenia (Glanzmann's) 287.1
- Thrombocythemia (essential) (hemorrhagic) (primary) (M9962/1) 238.7
- Thrombocytopathy (dystrophic) (granulopenic) 287.1
- Thrombocytopenia, thrombocytopenic 287.5
- Thrombocytosis, essential 289.9
- Thromboembolism - see Embolism
- Thrombopathy (Bernard-Soulier) 287.1
- Thrombopenia (see also Thrombocytopenia) 287.5
- Thrombophlebitis 451.9
- Thrombosis, thrombotic (marantic) (multiple) (progressive) (septic) (vein) (vessel) 453.9
- Thrombus - see Thrombosis
