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Chapter 1
Definition and classification of hypertension
Definition
Upper acceptable limit
for normal systolic blood pressure is less than 140 mmHg and for diastolic
blood pressure less than 90 mmHg. These are arbitrary cut points since
the relationship between blood pressure and cardiovascular risk is linear
without a threshold and the risks start at levels as low as 110/80 mmHg.
Classification
The classification
followed in these guidelines is similar to that of the WHO/ISH with minor
modifications (table 1).
The category of high
normal blood pressure, although it is not within the spectrum of hypertension,
should be identified and managed separately. Individuals with high normal
blood pressure were found to be at significantly greater risk to develop
future cardiovascular events than those with normal blood pressure. Clustering
of cardiovascular risk factors (e.g., diabetes, dyslipidemia, obesity,
impaired glucose tolerance) is more prevalent in this group than in individuals
with normal blood pressure.
Table
1. Classification of Blood Pressure
Levels
| Category |
Systolic |
Diastolic |
| Optimal |
<120 |
<
80 |
| Normal |
<130 |
<85 |
| High-normal |
130-139 |
85-89 |
| Grade
1 (Mild Hypertension) |
140-159 |
90-99 |
| Grade
2 (Moderate Hypertension) |
160-179 |
100-109 |
| Grade
3 (Severe Hypertension) |
>
180 |
>
110 |
| Isolated
Systolic Hypertension |
>
140 |
<90 |
Diagnosis
of Hypertension
- Diagnosis of hypertension is based
upon at least five office visits over a period varying from days to
months. The frequency of visits and period of blood pressure monitoring
is dictated by the severity of hypertension and cardiovascular risk
profile. Three visits are enough if the blood pressure is persistently
above 160/100 mmHg or if target organ damage is present.
- Blood pressure should be measured
accurately and under standardized conditions (see chapter 2).
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