The most widely used classification of blood pressure readings currently is given in the table below. Stratification of the blood pressure readings into different categories is important because of increasing severity of high blood pressure readings and different approach to the treatment of these conditions. Another table below the first one gives the blood pressure chart with different categories of the blood pressure, symptoms and the treatment.
Table 1: Blood Pressure Classification according to JNC 7
| Classification | Systolic BP | Diastolic BP |
|---|---|---|
| Normal Blood Pressure | 90 – 119 | and 60 – 79 |
| Prehypertension | 120 – 139 | or 80 – 89 |
| Stage 1 Hypertension | 140 – 159 | or 90 – 99 |
| Stage 2 Hypertension | ≥ 160 | or ≥ 100 |
| Isolated Systolic Hypertension | ≥ 140 | or < 90 |
BP – Blood Pressure, Values of blood pressure in mm Hg
Table 2: Blood Pressure Chart
| Condition | BP | Symptoms | Treatment |
|---|---|---|---|
| Low Blood Pressure (Hypotension) | Systolic <90 or Diastolic <60 | Dizziness, fatigue, exercise intolerance, fainting, shortness of breath, chest pain, pale skin, etc. | Treatment of cause. Borderline low BP with no obvious cause- Increased salt and water intake. Drugs if necessary |
| NORMAL | Systolic 90-119 or Diastolic <60-79 | ---- | ---- |
| Prehypertension | Systolic 120-139 or Diastolic 80-89 | NONE | Lifestyle Modifications |
| Stage 1 Hypertension | Systolic 140-159 or Diastolic 90-99 | No symptom in most of the cases. Headache, lightheadedness, palpitations and easy fatigability may occur. | Anti-hypertensive medications + Life style modifications |
| Stage 2 Hypertension | Systolic >160 or Diastolic >100 | Above symptoms more likely than Stage 1. Still many are asymptomatic. Other symptoms depending upon the complications. | Anti-hypertensive medications + Life style modifications |
| Extremely High Blood Pressure | Systolic 180 or Diastolic >110 | Headache, dizziness, palpitations, etc. if only elevated blood pressure present and no complications have occurred yet. Symptoms variable depending upon the specific type of hypertensive emergency. May cause immediate death. | Medical Emergency. BP needs to be lowered urgently with special Anti-hypertensive regimens. Complications (stroke, heart attack, encephalopathy, etc.) managed accordingly. Anti-hypertensive medications + Life style modifications afterwards for maintaining BP |
*All BPs (blood pressures) in mm of Hg.
Normal systolic blood pressure is 90 to 119 mm of Hg and normal diastolic blood pressure is 60 to 79 mm Hg. Even in this range, the lower blood pressure is better. So even if one has a blood pressure of 118/78 mm Hg, adopting a healthier lifestyle (quitting smoking, reducing alcohol, reducing weight if obese, exercises, reduced salt intake, healthier diet, etc.) is a good choice. However, self-medications to reduce the blood pressure further should never be attempted.
Systolic BP lower than 90 mm Hg or diastolic BP lower than 60 mm Hg is considered low blood pressure or hypotension. Unlike hypertension, hypotension is more likely to be due to a primary cause (dehydration, heart disease, drugs, endocrine disease, etc.) and thus therapy is often aimed at treating the primary cause. Borderline BP with no obvious cause can be treated with increased salt and water intake, regular mild exercises, cutting down on alcohol, etc.). Drug therapy can be used if such hypotension is not amenable to these measures.
Prehypertension is asymptomatic and currently anti-hypertensive drugs are not used for its treatment. Lifestyle modifications, if followed sincerely, are helpful and often bring down the blood pressure within the normal range.
Stage 1 and Stage 2 hypertensions require therapy with anti-hypertensive drugs to bring down the blood pressure. Lifestyle modifications are also necessary, but often it is not sufficient for satisfactory control of blood pressure. Hypertension is often asymptomatic in the early course of disease. Symptoms like headache, lightheadedness, palpitations and easy fatigability may occur and chances of them being present increases with increasing blood pressure.
Extremely high levels of blood pressure, i.e. systolic above 180 mm Hg or diastolic above 110 mm Hg requires immediate medical attention. Delayed treatment in such cases may result in various hypertensive emergencies like stroke, heart attack, hypertensive encephalopathy, malignant hypertension, aortic dissection, etc. These conditions may cause death.