Hypertension: the highs and the lows

The true figures could in fact be higher, especially in emerging nations where screening is poor.

Several trials have been undertaken over the years and the most recent, published in 2014, have provided new information on the optimal therapeutic approach to this common cardiovascular disease. The outcomes of these studies have also led the international societies of hypertension to revise their recommendations with regard to appropriate blood pressure control with medication. 

Hypertension is an excessive level of pressure against the artery walls. The high blood pressure progressively injures the inner structure of the arteries and favours the development of atherosclerosis, which leads to the build up of plaques of cholesterol, calcium and other substances that markedly narrow the arteries. As a result, affected arteries are unable to provide adequate blood supply and serious organ damage occurs especially within the heart, brain, kidneys and eyes. In the long term, untreated hypertension is responsible for potentially life-threatening complications including heart attack and stroke, as well as renal failure and reduced eyesight. 

In most cases, raised blood pressure does not lead to any symptoms. People may suffer from hypertension for years without noticing it. In rare cases, when blood pressure reaches very high levels, symptoms may appear and include chronic headache, spontaneous bleeding from the nose and dizziness. 

In less than 5 per cent of the cases, hypertension is a consequence of an underlying disease or the result of certain medications as well as addiction to illicit drugs or alcohol.

However, the majority of people have what is known as “essential hypertension”, meaning that no identifiable cause can be found. Essential hypertension usually occurs after 45 in men and after 65 in women. 

Risk factors that greatly favour the development of hypertension include being overweight or obese, physical inactivity, smoking, excessive alcohol intake or a salty diet. Avoiding these unhealthy conditions effectively prevents hypertension. 

Measuring the blood pressure is routine during any hospital visit. Blood pressure is assessed in millimetres of mercury (mm Hg) and has two numbers. The first one is called systolic pressure and corresponds to the level of pressure when the heart contracts to propel the blood into the arterial circulation, the second one measures the pressure between 2 contractions when the heart is resting and is referred as diastolic pressure. 

Normal blood pressure is 120/80 mm Hg. Higher than 140/90 mm Hg is hypertension. Between these figures, (120 to 139 and 80 to 89 mm Hg), it is called prehypertension that may over time develop into hypertension. 

In the past, many scientists considered that the lower the blood pressure, the better the efficacy of the treatment. But recent studies among adults from 18 to 59 years of age have shown that both individuals with too high blood pressure but also those with too low blood pressure figures are at risk of cardiovascular complications. In other words, while controlling blood pressure is primordial, the goal of anti-hypertensive therapy should be limited to reaching the 140/90 thresholds. In contrast with the past guidelines, it is now no longer appropriate to try to attain lower figures than 140/90 even for people afflicted with other atherosclerosis concerns such as diabetes and renal insufficiency. In addition, for the elderly, medications are needed only when the blood pressure exceeds 150/90 and the effective control of blood pressure for people over 60 years of age is to reach this target level of 150/90 only. 

As a whole, the new guidelines of hypertension treatment are less stringent in term of objectives of blood pressure control. However, despite this more flexible approach, hypertension remains too often undetected or inadequately treated. The revised recommendations still stress the need to improve the awareness and the screening of this disease among the population.

When was the last time, you had a blood pressure measurement? 

 

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 [email protected]