| NFNID | National Foundation for NonInvasive Diagnostics |
|---|---|
| NHF | National Health Federation; National Hemophilia Foundation; nonimmune hydrops fetalis |
| NHIF | National Head Injury Foundation |
| NMF | N-methylformamide; National Medical Fellowship; National Migraine Foundation; nonmigrating fraction |
| NRF | Neurosciences Research Foundation; normal renal function |