| Abbreviation | Definition |
|---|---|
| NHSTU | NHS Training Unit |
| NHSWMSHA | NHS West Midlands Strategic Health Authority |
| NI | name identity |
| NI | Narcotrend Index |
| NI | National Indicator |
| NI | natural immunity |
| NI | necroinflammatory |
| NI | necrosis index |
| NI | negative ion |
| NI | neointima |
| NI | neostriatum intermedium |
| NI | neural invasion |
| NI | neuraminidase inhibition |
| NI | neurogenic inflammation |
| NI | neuroimaging |
| NI | neurointermediate |
| NI | neurologic impairment |
| NI | neurologic improvement |
| NI | neurologically impaired |
| NI | neurologically intact |