| MER | mean ejection rate; medical emergency room; methanol extraction residue; murmur/energy ratio |
|---|---|
| MFR | mean flow rate; mucus flow rate |
| MHD | maintenance hemodialysis; mean hemolytic dose; mental health department; minimum hemolytic dilution;... |
| MLAP | mean left atrial pressure |
| MLR | mean length response; middle latency response; mixed lymphocyte reaction |