July 03, 2012 00:00
By Dr Gerard Lalande
Hypertension, otherwise known as high blood pressure, is one of the world's most common diseases, afflicting a third of US adults, for example.
The modern lifestyle with its excess of hyper-caloric food, sweet beverages and little physical activity contributes to its increase.
Hypertension is one of the leading factors behind such dreadful cardiovascular cardiac diseases as heart attack and stroke, which are among the main killers in the West.
The pressure of the blood within the arteries is measured in two numbers as millimetres of mercury (mm Hg). The higher one – systolic blood pressure – corresponds to the pressure level when the heart contracts and pushes the blood throughout the body. The lower one – diastolic – refers to the pressure point when the heart is at rest, between contractions. Both numbers are important when it comes to assessing your medical condition.
Your blood pressure (BP) is normal if it’s below 120/80 mm Hg. The initial stage of elevated BP is now called pre-hypertension, ranging from 120 to 139 for systolic BP and 80 to 89 for diastolic. Pre-hypertension tends to aggravate over time.
You become hypertensive when your BP is higher than 140/90. Stage 1 hypertension is between 140 and 159 / 90-99. When blood pressure hits or exceeds 160 / 100 it’s called Stage 2 hypertension, requiring prompt treatment.
Fewer than 5 per cent of cases involve secondary hypertension, stemming from an underlying pathology such as adrenal-gland tumours, defects on the renal artery or certain medication. Treating the cause normalises the blood pressure.
The rest of the cases – for which no cause can be found – are primary (or essential) hypertension. Blood pressure tends to gradually increase over the years. Any of the bodily systems that help control blood pressure – brain, heart, vessels, kidneys, various hormones – could be damaged.
Essential hypertension is a lifetime disease. It usually starts after 30 years of age and more often affects people with a family history of hypertension or those who smoke or are overweight, physically inactive, eat too much salt.
The gradual rise in blood pressure allows the body to “adapt”, so there are rarely any overt symptoms and the disease is often undiagnosed. It’s more likely to be discovered during a routine check-up.
In rare cases, hypertension can become a medical emergency, when the blood pressure abruptly exceeds 200. There’s a risk of artery rupture in the brain, and then haemorrhagic stroke.
Left untreated, essential hypertension significantly increases atherosclerosis – the progressive build-up of plaque containing cholesterol and calcium that progressively narrows the arteries. This vascular damage is responsible for most hypertension complications. Hypertension is also associated with other risk factors, such as high lipids, diabetes and obesity, all of which worsen atherosclerosis.
Doctors seek to normalise blood pressure while at the same time protecting the brain, heart and kidneys from hypertension’s ravages. Treatment always starts with lifestyle modification, which in some cases is enough to control blood pressure – a healthier diet, more exercise, no smoking, only moderate drinking. These habits must be maintained anyway if anti-hypertension medication is needed.
Dr Gerard Lalande is managing director of CEO-Health, which provides medical referrals for expatriates and customised executive medical check-ups in Thailand. He can be contacted at firstname.lastname@example.org.