| UE | uncertain etiology; under elbow; uninvolved epidermis; upper esophagus; upper extremity |
|---|---|
| URI | uniform resource identifier; upper respiratory illness; upper respiratory infection |
| US | screen unsharpness ultrasonic, ultrasound; ultrasonography; unconditioned stimulus; unique sequence;... |
| RL | radial line; radiation laboratory; reduction level; renal dysplasia-limb defects [syndrome]; resisti... |
| RLL | right lobe of liver; right lower limb; right lower lobe |