What Causes High Blood Pressure?
The cause of high blood pressure can be broadly classified into two categories:
- Primary hypertension or essential high blood pressure
- Secondary hypertension
Primary Hypertension: In this type of hypertension, there is no known cause of high blood pressure. It is the leading cause of high blood pressure in 95% of admitted cases. It tends to gradually develop over the years, and it is greatly influenced by a combination of genetic and environmental factors. These factors include:
- Age: The risk of developing high blood pressure increases with age. Until about age 64, high blood pressure is more common in men. Women are more likely to develop high blood pressure after age 65.
- Smoking: The chemicals found in tobacco can lead to the damage of the inner lining of the arterial blood vessel. This process leads to narrowing of blood vessels, resulting in higher blood pressure and also increases the risk of heart disease. Smoking also reduces the blood’s oxygen content so the heart has to pump faster in order to compensate, causing a rise in blood pressure.
- Physical inactivity: People who have a sedentary lifestyle or physically inactive tend to have higher heart rates. The opposite can be seen in trained athletes. The higher your heart rate, the harder your heart must work with each contraction and the stronger the force on your arteries. Lack of physical activity also increases the risk of being overweight
- Family history
- Ethnicity: There is enough evidence to support that black/African-American or South Asian ancestry have a higher risk of developing hypertension, compared to people with predominantly Caucasian or Amerindian (indigenous of the Americas) ancestries.
- Mental stress
- High salt intake: Evidence indicates that too much salt in your diet can cause your body to retain fluid, which increases blood pressure.
Secondary hypertension: High blood pressure is caused by an underlying condition. It tends to appear suddenly and is more severe than primary hypertension. Various conditions can lead to secondary hypertension, including
- Obstructive sleep apnea
- Kidney problems such as stenosis of the kidney artery.
- Adrenal gland tumors such as pheochromocytoma
- Thyroid problems
- Certain defects you’re born with (congenital) in blood vessels
- Certain medications, such as oral contraceptive pills, cold remedies, decongestants, over-the-counter pain relievers like NSAIDs and some prescription drugs
- Illegal drugs, such as cocaine and amphetamines
How to Lower Your Pressure Naturally
A critical step in preventing and lowering blood pressure is through lifestyle modification. This is always the first line recommendation for people with primary or essential hypertension. The advantages of lifestyle modification include a significant drug cost reduction, a beneficial effect on other medical drug treatment with its potential for adverse effects
Recommended lifestyle changes to naturally lower blood pressure include:
- Eating a healthy diet: including the DASH (Dietary Approach to Stop Hypertension). The DASH diet is low in total and saturated fat, red meat, sugar, sugary drinks, and refined carbohydrates, but high in fruits, vegetables, whole grains, fish, poultry, and low-fat dairy products. The DASH diet has been found to lower weight, heart rate, risk of type 2 diabetes, C-reactive protein, apolipoprotein B, and homocysteine and is associated with a lower incidence of heart failure, all-cause mortality, and stroke
- Limiting alcohol to two drinks a day for men, one drink a day for women
- Stop smoking.
- Getting regular aerobic exercise (such as brisk walking at least 30 to 60 minutes a day, several days a week) will help lower your blood pressure by 4 to 9mmHg. It is advised you consult with your doctor before starting any exercise or physical activity program. Your doctor will recommend programs tailored to your needs and health.
When to Start Medication
If your blood pressure rises into the range of hypertension, your doctor may start you on one or combination of anti-hypertensive drugs. People with prehypertension do not require medication unless they have other co-morbid conditions such as diabetes, coronary artery disease or chronic kidney disease.
These are some of the most common drugs used to treat hypertension
Angiotensin-converting enzyme (ACE) inhibitors. These medications such as lisinopril (Zestril), benazepril (Lotensin), captopril (Capoten) and others help relax blood vessels by inhibiting the formation of a natural hormone called angiotensin ii. This hormone narrows blood vessels, and increases blood flow, leading to increases in blood pressure People with chronic kidney disease may benefit from having an ACE inhibitor as one of their medications. ACE inhibitors should not be in pregnant women as it can lead to organ malformation in the fetus. It is also not recommended for people with a history of heart disease.
Common side effects associated with ACE inhibitors include dizziness, fatigue, weakness, headaches, persistent and irritating dry cough. Some patients that may find the side effects too unbearable. In such cases, your doctor will switch your medication to another class known as angiotensin-2 receptor blocker.
- Thiazide diuretics: are often the first, but not the only, choice in high blood pressure medications. They act on your kidneys to help your body eliminate sodium and water, reducing blood volume. Drugs in this group include chlorthalidone, hydrochlorothiazide (Microzide) and others.
Thiazide is very effective in lowering blood pressure even when used alone. If you’re taking a thiazide diuretic and your blood pressure remains high, talk to your doctor about adding one or replacing a drug you currently take with a diuretic. Diuretics or calcium channel blockers may work better for people of African heritage and older people than do angiotensin-converting enzyme (ACE) inhibitors alone. A common side effect of diuretics is increased urination.
- Calcium channel blockers (CCBs), works by decreasing the concentration of calcium in blood vessels. A fall in serum calcium concentration relaxes the vascular smooth muscle so that it does not contract so strongly, resulting in the dilatation of arteries and lowering of blood pressure. Drugs in this group includes amlodipine (Norvasc), diltiazem (Cardizem, Tiazac, others)
Patients with a history of heart disease, liver disease, or problems with circulation should not take calcium channel blockers. Grapefruit should not be taken with calcium channel blockers as it interacts with it, leading to increased blood levels of the drug
Falkner, B., Michel, S., & Kushner, H. (1999). Multiple Dietary Nutrients and Blood Pressure in Urban Adolescents at Risk for Cardiovascular Disease. Pediatric Research, 45(4, Part 2 of 2), 3A-3A. doi: 10.1203/00006450-199904020-00028
Stamler, J. (1991). Blood pressure and high blood pressure. Aspects of risk. Hypertension, 18(3_Suppl), I95-I95. doi: 10.1161/01.hyp.18.3_suppl.i95
Uncontrolled factors of blood pressure in essential hypertension: from“patient’s high blood pressure”to“hypertensive patient”. (2014). China Journal Of Chinese Materia Medica. doi: 10.4268/cjcmm20140736
Volpe, M. (2005). Application of Hypertension Guidelines in Clinical Practice. High Blood Pressure & Cardiovascular Prevention, 12(3), 193???194. doi: 10.2165/00151642-200512030-00173