- Thoracopagus 759.4
- Thoracoschisis 756.3
- Thoracoscopic surgical procedure converted to open procedure V64.42
- Thorax - see condition
- Thorn's syndrome (see also Disease, renal) 593.9
- Thornwaldt's, Tornwaldt's
- 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 (primary) (M9962/1) 238.71
- Thrombocytopathy (dystrophic) (granulopenic) 287.1
- Thrombocytopenia, thrombocytopenic 287.5
- Thrombocytosis 238.71
