Is blood pressure 140/90 mm Hg OK?
Supakorn Rojananin, M.D.
Deputy Dean of Public Relations and Special Affair,
Faculty of Medicine Siriraj Hospital
When we measure blood pressure (BP), we will report in 2 numbers, for example, 140 over 90 or 140/90 mm Hg. The top number is called systolic pressure which represents the intra-arterial pressure when the heart contracts and pumps blood carrying oxygen and nutrients to the body. The bottom number is called diastolic pressure which is the remaining pressure when the heart is relaxing between heartbeats.
In the past, blood pressure considered high when it is consistently exceeding 140/90 or greater and these people should be treated. But now, the guideline to take care hypertensive patients had been changed as well as the classification of high blood pressure.
According to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, USA (May 2003). Normal blood pressure for adults aged 18 years or older should be below 120/80. BP of 120-139/80-89 is considered as pre-hypertension. Stage 1 hypertension is 140-159 systolic pressure or 90-99 diastolic pressure and stage 2 hypertension is 160 or over systolic pressure or 100 or over diastolic pressure.
The introduction of pre-hypertension is to acknowledge the health care personnel and publics that these people should be well aware and their blood pressure should be carefully monitored or lowered before it developed hypertension.
If people leave their hypertension untreated or go uncontrolled, the consequences of cardiovascular diseases and organ damages will be occured causing more early life morbidity and mortality. Long time strain from high pumping pressure will cause the heart muscle become thickening especially on the left side (left ventricular hypertrophy) which eventually will interfere with the ability of the heart to pump the blood efficiently and increase the risk to develop heart failure.
Many other potential complications associated with uncontrolled hypertension are:
· Coronary artery disease (CAD), especially in patients who had associated diabetes, obesity, high cholesterol, drinking and smoking habit. The heart vessels become narrow by intra-luminal plaque of fatty substance until the symptoms show when the hearts do not get enough oxygen from blood.
· Stroke: Hypertension may cause the main blood vessels in the brain to burst or to be clogged by a blood clot or some other particle which leads to hemi-paresis due to the brain cell death. Since the dead brain cells are not replaced, the effects of a stroke are often permanent.
Hypertension can also damage or cause thickening of the wall of blood vessels in other main organs which cause the diseases such as, renal (kidney) failure, peripheral vascular diseases at the feet, legs, etc. and retinopathy (damaging blood vessels in the retina causing patchy vision loss)
Associate Professor, Dr. Peera Buranakitcharoen, Chief of Division of Hypertension, Department of medicine, Faculty of Medicine Siriraj Hospital discloses that, in 1996, 13% of Thai people aged 18-60 years had developed hypertension, only one third knew their conditions and were properly treated. This is due to the fact that most of people with hypertension do not have any symptoms at all. Some know their hypertension only when they have their BP checked.
Therefore some claim HT as a silent killer. Over 90% have unknown causes. Age, heredity and environmental factors including obesity, physical inactivity, diabetes mellitus, high blood cholesterol level, too much salt intake, alcohol and tobacco consumption and stress are among the risk factors.
Dr. Peera says the goal of therapy of hypertension is the reduction of cardiovascular and renal morbidity and mortality. Treating systolic BP and diastolic BP to targets that are less than 140/90 mm Hg is associated with a decrease in cardiovascular disease complications. In patients with diabetes or renal (kidney) disease, the BP goal is less than 130/80 mm Hg. Life style changes is critical for prevention of high BP including weight reduction in those individuals who are overweight or obese, reduction of dietary sodium (salt), caffeine , alcohol, physical activity and smoking cessation. Low saturated fat, high fiber intake (fruits and vegetables) may lower the cholesterol and insulin levels.
Drug therapy is needed when life style modifications fail to control the blood pressure. Many classes of drugs are available and may be used in combination such as diuretics, beta blockers, angiotensin-receptor blockers, calcium channel blockers, anti-platelet and cholesterol lowering agents. However, all the drug use and optimization of the dosages should be handled only by your physicians. Since hypertension is a chronic, life-long condition, regular check-up of your BP is mandatory and life style adjustment and your hypertensive treatment may be continued throughout your life.