What is high blood pressure?
High blood pressure or hypertension is a chronic disease wherein the arterial blood pressure is higher than normal. As a result, the heart has to pump harder than usual to circulate blood through the arteries and capillaries, which stresses the arterial walls and speeds up plaque formation.
Blood pressure (BP) is defined by two measurements that reflect the peak of heart muscle contraction, called systolic BP, and the relaxed phase of cardiac contraction, called diastolic BP.
The causes of hypertension are both biomedical and lifestyle oriented. While emotional or physical stress raises blood pressure transiently, diet, alcohol intake, tobacco smoking, and levels of physical activity affect longer-term blood pressure levels. The risk of disease increases as the level of blood pressure increases. A person with hypertension who smokes has a three-fold increased risk for heart attack and stroke.
Irrespective of the cause, persistently elevated blood pressure is a substantial causative factor in the development and progression of atheromatous plaque in the arteries, also called arteriosclerosis. High blood pressure is a major risk factor for coronary heart disease, stroke, heart failure, peripheral vascular disease, and chronic renal failure. Hypertension also results in end-organ damage and can lead to chronic renal failure, retinal damage of the eye, and brain atrophy.
A doctor or nurse can use a sphygmomanometer to measure arterial blood pressure, which is expressed in terms of systolic pressure over diastolic pressure measured in millimetres of mercury (mmHg), for example 110/60.
The normal range is from 100 to 140 mmHg for systolic BP and 60 to 90 mmHg for diastolic BP. Therefore, hypertension is diagnosed if the systolic BP persistently exceeds 140 mmHg or the diastolic BP persistently exceeds 90 mmHg.
High blood pressure is classified as either primary hypertension (essential hyper¬tension), which occurs in 90 to 95% of people with hypertension, or secondary hypertension, which occurs in 5 to 10% of people with hypertension. Secondary hypertension results because of another disease condition, such as chronic renal disease, diabetes, Cushing’s disease or other endocrine disorders.
Secon¬dary hypertension generally presents as a symptom of the primary disease process. However, primary hypertension is typically an asymptomatic disease, until substantial vascular or renal damage has occurred. Primary hypertension is often detected during a routine physical examination when a different medical problem is suspected, or as part of a physical ‘check-up’.
Conventional medical treatments doctors use to treat high blood pressure
Hypertension is a leading risk factor for preventable cardiovascular disease, with over one in five adults affected worldwide.
In most cases, a person with high blood pressure will need to take antihypertensive medication to keep blood pressure within the normal range. Antihypertensive medication is often gradually increased to determine the best combination and dose to achieve the best blood pressure control. More than one medication is usually needed. Fortunately any side effects are in most cases minimal.
A medical doctor will need to carefully manage antihypertensive medication and check blood pressure regularly to assess the effectiveness of medication. A person taking hypertension medication should not stop or alter medication doses without first discussing this intension with a doctor.
Antihypertensive medication can lower and manage high blood pressure but can’t cure the cause of hypertension. While the dose prescribed may vary over time, in most cases medication needs to be taken for the duration of life.
Many classes of antihypertensive medications have been developed to regulate blood pressure, including thiazide diuretics, ACE inhibitors, calcium channel blockers, beta blockers, and angiotensin II receptor antagonists.
Drug therapy is justified for a person with high pressure at high risk of heart attack and stoke. However, drug therapy should not obviate changes to a healthier lifestyle, including a more nutritious diet and regular exercise.
All classes of antihypertensive drugs have similar efficacy, but some work better than others, depending on individual response. The target blood pressure range might take time to reach and usually more than one drug is required to reach the target.
Secondary hypertension results because of the effects of another medical disorder or medication, so the primary cause requires treatment as well. Secondary hypertension may be due to:
- Chronic kidney disease
- Disorders of the adrenal gland, such as a pheochromocytoma tumour or Cushing syndrome
- Pregnancy or preeclampsia
- Medications such as birth control pills, diet pills, some cold medicines, and migraine medicines
- Renal artery stenosis – narrowing of the artery to the kidney
Nutritional medicine treatment for high blood pressure
High blood pressure is a pervasive and devastating health threat to the aging population. Around 30% of the aging population don’t realize their blood pressure levels are above normal. For the nutritional medicine practitioner treating high blood pressure, there are several points of special note.
The most commonly advised nutritional therapeutic inter vention for essential hypertension is to restrict sodium intake and increase potassium intake. This advice is based on the positive association between blood pressure and salt intake and the negative association between blood pressure and potassium intake reported by intercultural epidemiological studies.
However, the most comprehensive and largest of these studies, the Intersalt Study, assessed 10,000 people across 52 different countries and demonstrated only a weak relationship between salt intake and blood pressure, which was partly attributable to variations in body-weight and alcohol intake.
Multiple studies within single countries report little or no correlation between salt intake and blood pressure and people with established essential hyper-tension exhibit no significant variation in salt or potassium intake from normotensive people. In addition, intervention studies have demonstrated that clinically achievable salt restriction in hypertensive patients produces only mild and variable blood pressure reduction that is of questionable clinical significance.
A person can control blood pressure, reduce the risk of heart disease and stroke, and improve the effectiveness of antihypertensive medication by implementing a number of lifestyle changes. In fact, a person with mild hypertension might be able to regulate normal blood pressure simply by making healthier lifestyle choices.
According to the Stroke Foundation, “two out of five people can successfully lower their blood pressure by making adjustments to their lifestyle”. Eating a high-fibre, low-fat, and low-salt diet, exercising regularly, limiting alcohol, maintaining an optimal weight, and quitting smoking have all been shown assist with blood pressure control.
The goals of nutritional medicine treatment of high blood pressure are to prevent hypertension and to control blood pressure in people who have hypertension.