| Cu | urea clearance |
|---|---|
| UC | ulcerative colitis; ultracentrifugal; umbilical cord; unchanged; unclassifiable; unconscious; undiff... |
| UCL | ulnar collateral ligament; upper collateral ligament; upper confidence limit; upper control limit; u... |
| Cm | maximum clearance |
| Dmax | maximum denaturation; maximum diameter |