NIH Pain Scale Gradations
| Gradation | Descriptor |
| 0 | No pain |
| 1–3 | Mild pain (nagging, annoying, interfering little with ADLs) |
| 4–6 | Moderate pain (interferes significantly with ADLs) |
| 7–10 | Severe pain (disabling; unable to perform ADLs) |
ADLs = activities of daily living.