| TLR | tonic labyrinthine reflex |
|---|---|
| TNR | tonic neck reflex; true negative rate |
| TTR | transthoracic resistance; transthyretin; triceps tendon reflex |
| TVR | tonic vibratory reflex; total vascular resistance; tricuspid valve replacement |
| UR | unconditioned reflex; upper respiratory; uridine; urinal; urology; utilization review |