Obese people stand a higher chance of developing hypertension. Medical student Sahra Haji outlines how high blood pressure is measured, its causes, prevention and possible treatment.

If one’s waist is too big when compared to one’s hips, one is at a higher risk of type 2 diabetes and ischaemic heart disease.

Have you heard of the silent killer? A disease so deadly you may not know it’s there until it can kill you? This is hypertension or high blood pressure.

When you have hypertension, your blood passes through the arteries with a higher force than normal. However, you cannot feel this force increasing, so how would you know you have hypertension?

Thankfully, this can be measured by a doctor during a regular check-up using a special device called a sphygmomanometer, or sphygmo for short.

The blood pressure measurement given is made up of two numbers, both measured in mmHg. The higher number is the systolic blood pressure, the pressure needed for your heart to squeeze and push blood everywhere it is needed in the body.

The lower number is the diastolic blood pressure, the pressure in your heart when it relaxes. The ideal blood pressure is 120/80mmHg or less. Hypertension results when the blood pressure stays above 140/90mmHg. This is ≥140mmHg systolic blood pressure and/or ≥90mmHg diastolic blood pressure.

Over time, this blood pressure may get higher and higher, leading to higher grades of hypertension (as shown in the table).

When one is obese, there is a higher chance of developing hypertension. The World Health Organisation defines obesity as having a body mass index (BMI) of 30kg/m2. This value is calculated by measuring your height in metres and weight in kilogrammes. The value of your weight is then divided by the square of your height.

Having a large BMI shows that you are too large for your height. As a result, the bones of your legs may not be able to support your weight since they can become weaker.

Doctors also check whether your waist is too big when compared to your hips. In that case, your fat distribution is central and one is at a higher risk of type 2 diabetes and ischaemic heart disease. Both these diseases can have complications leading to hypertension.

The way obesity itself causes hypertension is still under research. Obesity causes fat build-up around blood vessels and organs, like the heart, and under the skin. Therefore, the heart has to work against the fat to push the blood through.

Those lovely salty crisps or biscuits, or regular cigarette breaks could be slowly killing you

Hypertension does not have symptoms on its own. Nonetheless, if your blood pressure remains uncontrolled and high over a long time, it damages the blood vessels in different parts of the body.

It makes the walls of the arteries harder and less stretchy. The blood struggles to pass through the arteries, so your heart needs to push abnormally harder. Therefore, you begin to suffer from the consequences of hypertension. And this, you may feel – headaches, eyesight problems and blindness, heart attacks, strokes and kidney failure.

The cause of most cases of hypertension, about 95 per cent, is not known. The remaining five per cent of hypertension cases are caused by obesity as highlighted above, kidney and blood vessel problems, pregnancy, ageing, stress, certain tumours and drugs like steroids.

Too much salt in your food and smoking also cause hypertension. So, those lovely salty crisps or biscuits, or regular cigarette breaks could be slowly killing you.

If you are diagnosed with diabetes, the doctor will normally give you medication known as an ACE inhibitor to keep your blood pressure low in addition to your regular diabetes medication.

There’s only so much drugs can do and every drug has its own side effects. Therefore, the first step in treating hypertension is a change in lifestyle.

Stop smoking, stop eating foods that contain too much salt and fat and try to lose weight, especially if you are obese. Exercise more regularly. Arteries will stop worsening and the heart will become stronger. There will be less of you for your legs to carry, so your bones will stop deteriorating.

The blood pressure gets higher when there is more blood to push through the body or when the arteries are smaller or when the heart beats faster. These are the three things that can be controlled by medications. ACE inhibitors, like enalapril or Coversyl, and angiotensin-receptor blockers, like losartan and candesartan, stop arteries from getting smaller and lower the amount of blood the heart has to push around the body.

Diuretics, like indapamide and bendroflumethiazide, also reduce the amount of blood the heart has to push around the body.

Beta blockers, like atenolol,calcium channel blockers, like amlodipine, and alpha blockers, like doxazosin, lower the heart rate.

Many patients will require more than one type of long-term medication to control their hypertension. The drugs given will depend on your specific needs and how much lower it is even possible for your blood pressure to become. Your doctor will guide you on this.

Also, it is important to take your medication as instructed by your doctor, even if you believe you are feeling better or no longer think you need medication.

Remember, unless you have already suffered a complication of hypertension, you will not feel a thing with treatment.