Blood pressure should be measured every two years starting at age 18; every year if over 40 or is 18 to 39 with a high risk of high blood pressure
Today is World Hypertension Day. Hypertension is currently one of the most serious health issues that require priority attention due to the large number of severe complications that can arise from this little understood and often misunderstood condition. It is also a silent killer as many persons with hypertension are unaware they suffer from this condition till they develop complications.
Senior Consultant and Diabetician Dr Prasad Katulanda tells the Sunday Observer why Hypertension deserves special focus and how it can be prevented and controlled if detected early by following some simple rules.
Excerpts…
Q. What is hypertension? There are many definitions of the word. What is the medical definition?
A. Hypertension is a condition where the blood pressure of an individual is elevated over a period of time. Such long-term elevation of blood pressure can lead to many complications
Q. What determines the blood pressure?
 Dr Prasad Katulanda |
A. The blood pressure is determined by the amount of blood pumped out of the heart (cardiac output) and the amount of resistance exerted by the walls of the blood vessels. When the amount of the blood pumped out is increased or the arterial walls become stiff and more resistance is exerted to the blood inside, the blood pressure increases.
Q. What are the normal blood pressure values?
A. The blood pressure can vary among different people as well as in the same person at different times. Blood pressure is low when a person is sleeping or at rest. It can go higher during exercise, when excited or when angry.
Q. Why is blood pressure important?
A. Certain amount of pressure inside blood vessels is important for the forward flow of blood inside blood vessels. If this is too low vital organs like the brain may not get sufficient amount of blood and the person may get a faintish feeling and even lose consciousness or die. In contrast too much elevated blood pressure can cause long term complications.
Q. Is hypertension common?
A. Hypertension is a very common condition. It affects more than 25% of adults in most countries in the world. The percentage of hypertension is higher in older people.
Q. Are there different causes or types of hypertension?
A. The commonest type of hypertension is called primary or essential hypertension. This occurs in mostly middle aged or older adults with a family history of hypertension. In essential hypertension no obvious single cause can be identified but there are risk factors for essential hypertension.
Q. What are the risk factors for hypertension?
A.
1. Age: As one grows older blood vessels loose elasticity and become stiff. This increases peripheral resistance to blood.
2. Family history of hypertension: Those who have first degree relatives with hypertension have a higher risk of developing hypertension.
3. Being overweight or obese: As one becomes overweight or obese more blood is needed to supply oxygen and nutrients to your tissues. Therefore, the volume of blood circulated through the blood vessels increases increasing the pressure.
4. Being physically inactive: Lack of physical activity increases the risk of being overweight. In addition people who are sedentary tend to have higher heart rates.
Q. What about smoking and chewing tobacco?
A. Smoking in any form or chewing tobacco immediately raises the blood pressure temporarily. In addition, the harmful chemicals in tobacco damage the lining of artery walls (endothelium). This causes a phenomenon called endothelial dysfunction and can cause stiffness of the arteries.
Q. Any other risk factors that can elevate blood pressure? Dietary habits, for example?
A. Too much salt (sodium) in the diet. Sodium in our diet leads to retainng more fluid which increases blood pressure. Too little potassium in the diet. Potassium helps to balance the amount of sodium in our cells. If we don't get enough potassium in the diet or retain enough potassium, too much sodium can accumulate in our blood.
Q. So what’s the solution?
A. Eat plenty of green leafy vegetables and fruits which are rich sources of potassium.
Q. Is alcohol also a contributory cause?
A. Excessive use of alcohol i.e. having more than one drink a day for women and more than two drinks a day for men can affect the blood pressure.
Q. I understand that people who don’t sleep enough and stress in any form can also lead to blood pressure. Is this correct?
A. Sleep deprivation can cause hypertension in disrupting the neuro-hormonal balance. High levels of stress can lead to increase in blood pressure.
Q. The term secondary hypertension is often confusing and many patients don’t understand it. What is Secondary hypertension? Why is it important? Is it a common condition?
A. When a definite cause can be identified for the blood pressure it is called secondary hypertension. The importance of identifying secondary hypertension is that if the cause can be identified early the blood pressure may be reversible or curable.
Q. What causes secondary hypertension?
A. Kidney disease. Hormone secreting tumors especially of adrenal gland. Obstructive sleep apnea. Thyroid disease. Certain defects in the blood vessels. Medications, such as pain killers, birth control pills, decongestants and some prescription drugs. Illegal drugs, such as cocaine and amphetamines
Q. In general what are the symptoms of hypertension?
A. Hypertension is mostly asymptomatic and this can go on for years like that. When the blood pressure is very high or occurs over a short period of time like in secondary hypertension some patients can develop symptoms such as headache, visual symptoms, difficulty breathing, heaviness of the chest, nose bleeds and blood passing in the urine.
Q. Are they visible immediately? Or will they remain undetected till it is too late?
A. You can have high blood pressure (hypertension) for years without any symptoms. Even without symptoms, damage to blood vessels and your heart continues and can be detected.
Q. What are the health risks from uncontrolled blood pressure?
A. Uncontrolled high blood pressure increases your risk of serious health problems, including heart attack and stroke.
Q. Complications of hypertension in general?
A. The excessive pressure on the artery walls caused by high blood pressure can damage blood vessels in many organs in the body. When the blood pressure is higher, occurs over a shorter period and goes uncontrolled longer, the greater the damage.
Q. Sum up for us the complications due to uncontrolled high blood pressure
1. Heart attack or angina – when the hypertension goes uncontrolled the inner layer of the blood vessels become dysfunctional and cholesterol rich deposits (atherosclerotic plaques) make the blood vessels narrower. When such a plaque ruptures one can develop a heart attack.
2. Stroke – high blood pressure can cause stroke due to blood clots (infarctions) as well as due to internal bleeding in the brain as a result of rupture of a blood vessel.
3. Heart failure – When heart pumps blood against the higher pressure in the vessels, the heart has to work harder. This gradually thickens the walls of the heart's pumping chamber (left ventricular hypertrophy). Ultimately , the thickened muscle becomes weaker and leads to heart failure.
4. Kidney failure – long standing hypertension damages the blood vessels in the kidneys and can cause kidney failure.
5. Vision loss due to thickened, narrowed or torn blood vessels in the eyes.
Q. Is it true that hypertension is also linked to Dementia?
A. Narrowed or blocked arteries eventually limit blood flow to the brain, leading to a certain type of dementia (vascular dementia). Strokes that affect blood flow to the brain also can cause vascular dementia.
Q. So how early and when do we need to check our blood pressure?
A. Blood pressure should be measured at least every two years starting at age 18. In those aged 40 or older, or is 18 to 39 with a high risk of high blood pressure, a blood pressure reading must be taken every year.
Q. Lifestyle changes can they help to control blood pressure?
A. Diet – The dietary approach to reduce stop hypertension (DASH diet) is widely recommended to reduce the blood pressure. The DASH diet encourages to reduce the sodium in the diet and to eat food rich in potassium, calcium and magnesium.
The DASH diet also emphasizes green vegetables, fruits, low-fat dairy foods and moderate amounts of whole grains, fish, poultry and nuts.
Since DASH diet is a healthy way of eating, it has health benefits besides just lowering blood pressure. The DASH diet also helps prevent diabetes, cancer, heart disease and stroke. Reduce added sugar, which has no nutritional value but can pack on calories, alcohol and caffeine. Drinking too much alcohol can increase blood pressure. Apart from that physical activity also helps.
Q. How does commonly used medications act and what are their common side effects.
A. A number of therapeutic agents are used for the treatment of hypertension. Diuretics especially of the thiazide group are used commonly. They act by increasing sodium excretion from urine and sometimes they can cause low sodium levels in blood. Drugs such as angiotensin converting enzyme inhibitors (ACEIs) and angiotensin-receptor blockers (ARBs) act by reducing the secretion of the hormone Aldosterone that is involved in sodium absorption in kidneys.
ACEIs can sometimes cause a dry cough and both can cause high potassium in some patients. Calcium channel blockers (CCBs) act mainly by dilating the blood vessels and reducing peripheral resistance of blood vessels.
Therefore, some CCBs can cause mild swelling around ankles. Some CCBs and beta-blockers act mainly by reducing the heart rate and the forcefulness of the contraction of the heart. They slow down the heart rate.
The class known as alpha blockers acts inhibiting alpha adrenergic receptors which act to constrict the blood vessels. Therefore alpha blockers act by dilatation of blood vessels. There are some anti hypertensives that act at the level of the brain to reduce the action of the sympathetic nervous system.
Q. Briefly sum up the golden rules for lowering blood pressure.
A. Moderate aerobic physical activities at least half an hour 5 days a week is helpful to reduce blood pressure. Adequate sleep – sleeping at least 6 hours a day is helpful to control high blood pressure.
Finally, Stress management – learning relaxation techniques, listening to soothing music, yoga and meditation may have favourable effects on hypertension.