It’s a health metric that’s constantly spoken about, measured at every visit to a doctor’s office and, in India, increasingly a cause of concern, but how much do you really know about blood pressure? What exactly does it measure? What do the numbers indicate? And why is it so important to keep these numbers in check?
Read on, to find out.
What is blood pressure?
Blood pressure is a measurement of the force of the blood against the walls of blood vessels (arteries). Your heart functions like a pump: sending blood to all the other parts of the body, supplying oxygen and nutrients to all your cells, and carrying away the waste. Your heart beats about 1,00,000 times a day and pumps about 5 litres of blood around your body. The blood is carried through a network of vessels known as arteries and veins. Arteries carry oygenated blood from your heart to the rest of your body, while veins carry dexoygenated blood from various parts of the body back to the heart. When your heart beats, it pumps blood into the arteries — it is the measurement of this pressure inside the arteries that is your blood pressure.
How is it measured?
Blood pressure is measures in millimetres of mercury, or mm HG. There are two numbers on the reading. The first number, systolic, represents the pressure in the blood vessels, when the heart beats (contracts). The second number, diastolic, is the pressure in the vessels, when the heart is at rest, between beats. A normal blood pressure reading is considered to be 120/80 mm HG. Anything above these values is considered unhealthy. According to the Standard Treatment Guidelines for hypertension brought out by the Union Health Ministry in 2016, hypertension, or high blood pressure, should be diagnosed when the blood pressure is persistently above a systolic of 140 mm and/or diastolic of 90 mm.
The guidelines state that a diagnosis of hypertension should be based on at least two measurements taken in the clinic or by a healthcare provider on at least two visits, which are at least 1-4 weeks apart, except in the case of hypertensive urgencies and hypertensive emergencies, where hypertension is diagnosed during the first visit itself.
What are the different categories of hypertension?
The Standard Treatment Guidelines classify hypertension into the following categories:
| Category | Systolic Blood Pressure (mm Hg) | Diastolic Blood Pressure (mm Hg) |
| Optimal | <120 | and <80 |
| Normal | 120 – 129 | and/or 80 – 84 |
| High Normal | 130 – 139 | and/or 85 – 89 |
| Grade 1 Hypertension | 140 – 159 | and/or 90 – 99 |
| Grade 2 Hypertension | 160 – 179 | and/or 100 – 109 |
| Grade 3 Hypertension | ≥ 180 | and/or ≥110 |
| Isolated Systolic Hypertension | ≥ 140 | and < 90 |
| Hypertensive urgency | >180 | and/or >110 |
| Hypertensive emergency | >180 | and /or >110-120 |
Why is measuring hypertension important?
A person’s blood is not uniform throughout the day, all day: it may fluctuate, for instance, going up when you exercise or are excited, going down while resting. The numbers may also vary based on age, medications being taken, stress, and the position the person is in — which is why, the guidelines emphasise that patients being measured for their blood pressure should be in a relaxed state for five minutes prior to the measurement, and must be seated in a particular position.
Measuring blood pressure is important, because hypertension (high blood pressure) is a silent killer — meaning there are generally no symptoms of it and it is a major cause of premature death worldwide. When your blood pressure is consistently high over a sustained period of time, it can damage your arteries, and is a key risk factor for cardiovascular diseases as well as kidney disease.
What are the risk factors for hypertension?
Your risk of having hypertension is high if you have a family history of hypertension. Other risk factors include: being obese, having diabetes, being over the age of 60, using tobacco products, not being physically active, eating foods that have high salt content and drinking too much alcohol.
According to the National Family Health Survey – 5 (2019-21), 24% of the population reported having elevated blood pressure or said they were taking medicine to control blood pressure. Worryingly, a large number of people with hypertension in India do not know they have it, and even among those who do, only a small proportion have it well under control: a systematic review published in The Lancet Regional Health Southeast Asia found that in the period between 2016 and 2020 less than one-fourth of people with high blood pressure in India had it under control.
What are the consequences of hypertension?
According to the World Health Organization, among other complications, hypertension can cause serious damage to the heart. Excessive pressure of blood flow can harden arteries, decreasing the flow of blood and oxygen to the heart. This elevated pressure and reduced blood flow can cause: chest pain, also called angina; heart attack, which occurs when the blood supply to the heart is blocked and heart muscle cells die from lack of oxygen. The longer the blood flow is blocked, the greater the damage to the heart; heart failure, which occurs when the heart cannot pump enough blood and oxygen to other vital body organs; and irregular heart beat which can lead to a sudden death.
This apart hypertension can cause strokes when arteries that supply blood and oxygen to the brain burst, or get blocked.
Hypertension can also cause kidney damage, leading to kidney failure
How is hypertension treated?
Your doctor may recommend lifestyle changes to help lower your blood pressure and these may include: a healthy, balanced diet that cuts down on salt, losing weight and regular physical activity, limiting alcohol, not smoking or using tobacco and getting adequate sleep. There are also a number of medications used to treat high blood pressure and these may be prescribed depending on how high your blood pressure is, your age and other factors.
How do you prevent hypertension?
Preventing hypertension can go a long way towards ensuring overall health and well-being. Eating more fruits and vegetables and cutting down on salty food as well as food that is high in saturated and trans fats can help, as can becoming more physically active (150 minutes of exercise per week), losing weight, cutting down on alcohol, managing stress, taking all prescribed medication, avoiding tobacco and reducing exposure to polluted air.
Checking one’s blood pressure on a regular basis is also vital: anyone over the age of 18 should have it checked when they visit a healthcare provider, and those over the age of 40 or those younger, but who have risk factors, must have it checked at least once a year.
Published – April 15, 2025 05:14 pm IST
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