| Severity grading |
Clinical features |
| Grade I |
Pre-hypertension (systolic blood pressure 120-139 mmHg, or diastolic blood pressure 80-89 mmHg. |
| Class II |
Stage I hypertension (systolic blood pressure 140 to 159 mmHg, or diastolic blood pressure 90 to 99 mmHg); requires medical intervention; recurrent or persistent (>24-hour) hypertension with symptomatic diastolic elevation >20 mmHg, or blood pressure >140/90 mmHg (in those with previously normal blood pressure); requires monotherapy. |
| Class III |
Stage II hypertension (systolic blood pressure ≥ 160 mmHg, diastolic blood pressure ≥ 100 mmHg) requiring medical intervention and multiple medications. |
| Grade IV |
Life-threatening (e.g., hypertensive crisis), requiring urgent treatment. |
| Grade V |
Death. |
Note: Grading criteria used National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE 4.0); 1 mmHg = 0.133 kPa .