In the United States, approximately 85 million people have high blood pressure – about 1 in every 3 adults over 20, according to the American Heart Association (AHA).
The National Institutes of Health (NIH) estimate that about two-thirds of people over the age of 65 in the U.S. have high blood pressure.
If left untreated or uncontrolled, high blood pressure can cause many health problems. These conditions include heart failure, vision loss, stroke, and kidney disease.
The heart is a muscle that pumps blood around the body.
Blood that has low oxygen levels is pumped towards the lungs, where oxygen supplies are replenished. The oxygen rich blood is then pumped by the heart around the body to supply our muscles and cells. The pumping of blood creates pressure.
If a person has high blood pressure, it means that the walls of the arteries are receiving too much pressure on a constant basis.
The causes of high blood pressure are divided into two categories:
- Essential high blood pressure: This has no established cause.
- Secondary high blood pressure: There is an underlying cause.
Even though there is no identifiable cause for essential high blood pressure, there is strong evidence linking some risk factors to the likelihood of developing the condition.
Most of the causes below are risk factors for essential high blood pressure. There are also examples of secondary high blood pressure:
The older you are the higher your risk of having high blood pressure.
2) Family history
If you have close family members with hypertension, your chances of developing it are significantly higher. An international scientific study identified eight common genetic differences that may increase the risk of high blood pressure.
A study that monitored 8,801 participants over the age of 65 found that systolic and diastolic blood pressure values differed significantly across the year and according to the distribution of outdoor temperature. Blood pressure was lower when it got warmer, and rose when it got colder.
4) Ethnic background
Evidence indicates that people with African or South Asian ancestry have a higher risk of developing hypertension, compared to people with predominantly Caucasian or Amerindian (indigenous of the Americas) ancestries.
5) Obesity and overweight
Both overweight and obese people are more likely to develop high blood pressure, compared to people of normal weight.
6) Some aspects of gender
In general, high blood pressure is more common among adult men than adult women. However, after the age of 60 years both men and women are equally susceptible.
7) Physical inactivity
Lack of exercise, as well as having a sedentary lifestyle, raises the risk of hypertension.
Smoking causes the blood vessels to narrow, resulting in higher blood pressure. 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.
9) Alcohol intake
People who drink regularly have higher systolic blood pressure than people who do not, according to researchers. They found that systolic blood pressure levels are about 7 millimeters of mercury (mmHg) higher in people who drink frequently than in people who do not drink.
10) High salt intake
Researchers reported that societies where people do not eat much salt have lower blood pressures than places where people eat a lot of salt.
11) High fat diet
Many health professionals say that a diet high in fat leads to a raised high blood pressure risk. However, most dietitians stress that the problem is not how much fat is consumed, but rather what type of fats.
Fats sourced from plants such as avocados, nuts, olive oil, and omega oils are good for you. Saturated fats, which are common in animal-sourced foods, as well as trans fats, are bad for you.
12) Mental stress
Various studies have offered compelling evidence that mental stress, especially over the long term, can have a serious impact on blood pressure. One study suggested that the way that air traffic controllers handle stress can affect whether they are at risk of developing high blood pressure later in life.
People with diabetes are at a higher risk of developing hypertension. Among people with type 1 diabetes, high blood sugar is a risk factor for incident hypertension – effective and consistent blood sugar control, with insulin, reduces the long-term risk of developing hypertension.
People with type 2 diabetes are at risk of hypertension due to high blood sugar, as well as other factors, such as overweight and obesity, certain medications, and some cardiovascular diseases.
A study that followed 78,000 women for 14 years found that having psoriasis was linked to a higher risk of developing high blood pressure and diabetes. Psoriasis is an immune system condition that appears on the skin in the form of thick, red scaly patches.
Pregnant women have a higher risk of developing hypertension than women of the same age who are not pregnant. It is the most common medical problem encountered during pregnancy, complicating 2 to 3 percent of all pregnancies.
Signs and symptoms
Most people with high blood pressure will not experience any symptoms. It is often known as the “silent killer” for this reason.
However, once blood pressure reaches about 180/110 mmHg, it is considered a medical emergency known as a hypertensive crisis. At this stage, symptoms will show, including:
- blurred or double vision
- palpitations, or irregular or forceful beating of the heart
Anybody who experiences these symptoms should see their doctor immediately.
Children with high blood pressure may have the following signs and symptoms:
- blurred vision
- Bell’s palsy, or an inability to control facial muscles on one side of the face.
Newborns and very young babies with high blood pressure may experience the following signs and symptoms:
- failure to thrive
- respiratory distress
People who are diagnosed with high blood pressure should have their blood pressure checked frequently. Even if yours is normal, you should have it checked at least once every five years, and more often if you have any contributory factors.
If the hypertension is not treated or controlled the excessive pressure on the artery walls can lead to damage of the blood vessels (cardiovascular disease), as well as vital organs. The extent of damage depends on two factors; the severity of the hypertension and how long it goes on for untreated.
Below is a list of some of the possible complications of high blood pressure:
- heart attack and heart failure
- blood clots
- kidney disease
- thickened, narrow, or torn blood vessels in the eyes
- metabolic syndrome
- brain function and memory problems
Treatment for high blood pressure depends on several factors, such its severity, associated risks of developing stroke or cardiovascular, disease, etc.
Slightly elevated blood pressure
The doctor may suggest some lifestyle changes if blood pressure is only slightly elevated and the risk of developing cardiovascular disease considered to be small.
Moderately high blood pressure
If blood pressure is moderately high and the doctors believes the risk of developing cardiovascular disease during the next ten years is above 20 percent, the doctor will probably prescribe medication and advised on lifestyle changes.
If blood pressure levels are 180/110 mmHg or higher, the doctor will refer the individual to a specialist.
Changes in lifestyle can help lower high blood pressure
The following are recommended lifestyle changes that can help you lower your blood pressure. Note that you should always check with a Doctor or healthcare professional to discuss lifestyle changes before making any dramatic changes yourself.
Exercising for 30 to 60 minutes five days a week will usually lower a person’s blood pressure by 4 to 9 mmHg. If you embark on an exercise program you should see the benefits fairly soon – within a matter of two to three weeks, especially if you have been leading a sedentary lifestyle for a long time.
It is important to make sure you check with your doctor before embarking on any physical activity program. Exercise needs to be tailored to the needs and health of the person with hypertension.
The secret of getting success out of exercise is to do it regularly. Exercising at weekends and doing nothing from Monday to Friday will be much less effective.
Studies have revealed that even moderate weight loss – just ten pounds – can have a significant impact in lowering elevated blood pressure.
If you are overweight, the nearer you get to your ideal weight the more your blood pressure is likely to fall. Any high blood pressure medications you are taking will become more effective when you lose weight.
Reducing your waistline will have the greatest effect. Achieving a healthy body weight involves a combination of exercise, good diet, and at least 7 hours good quality sleep each night.
Scientists at Kaiser Permanente’s Center for Health Research discovered that keeping a food diary can double weight loss as part of a managed program.
Researchers at Massachusetts General Hospital found that adding the relaxation response, a stress-management approach, to other lifestyle modifications may significantly improve treatment of the type of hypertension most common in the elderly.
Harvard Women’s Health Watch reported that in one study, tai chi significantly boosted exercise capacity, lowered blood pressure, and improved levels of cholesterol, triglycerides, insulin, and C-reactive protein in people at high risk for heart disease.
Not getting enough sleep can increase a person’s risk of developing high blood pressure, scientists from the University of Chicago reported after monitoring over 500 middle aged people for 5 years.
Some studies have suggested that adults sleep no less than 7 hours and no more than 8 hours per day. In 2008 the American Academy of Sleep Medicine published a study suggesting that people with sleep duration above or below the recommended 7-to-8 hours per night face an increased risk of hypertension.
There are several anti-hypertensive medications on the market today. Some people may need to take a combination of different drugs to effectively control their high blood pressure.
Some people may have to be on medication to control hypertension for the rest of their lives. Doctors may advise discontinuing treatment if the individual has managed to maintain good blood pressure levels for a given period, and is not considered to be at significant risk of stroke or cardiovascular disease.
One study found that people have more control of their high blood pressure when treated with less medication.
These are some of the most common drugs for treating high blood pressure:
1) Angiotensin-converting enzyme (ACE) inhibitors
ACE inhibitors block the actions of some hormones, such as angiotensin II, that regulate blood pressure. Angiotensin II causes the arteries to constrict, and increases blood volume, resulting in increased blood pressure.
People with a history of heart disease, pregnant women or individuals with conditions that affect the blood supply to the kidneys should not take ACE inhibitors.
Doctors may order a blood test to determine whether the patient has any pre-existing kidney problems. ACE inhibitors can reduce the blood supply to the kidneys, making them less efficient, therefore regularly blood tests are required.
ACE inhibitors may have the following more common side effects, which usually go away after a few days:
- persistent dry cough that may continue
Some patients may find the side effects too unpleasant or long-lasting. In such cases doctors will switch to an angiotensin-2 receptor antagonist. Side effects are less common, but may include dizziness, headache and increased potassium levels in the blood.
2) Calcium channel blockers
Calcium channel blockers (CCBs), among other things, decrease the calcium in blood vessels. A drop in calcium relaxes the vascular smooth muscle so that it does not contract so strongly, resulting in the widening of arteries. If the arteries are wider blood pressure will drop.
Patients with a history of heart disease, liver disease, or problems with circulation should not take calcium channel blockers.
Calcium channel blockers may have the following more common side effects, which usually go away after a few days:
- redness of the skin, usually over the cheeks or neck
- swollen ankles, feet, and more rarely the abdomen
- skin rash
3) Thiazide diuretics
Thiazide diuretics act on the kidneys to help the body eliminate sodium and water, resulting in less blood volume – less blood volume results in lower blood pressure. They are often the first choice in high blood pressure medications (but not the only choice).
Thiazide diuretics may cause the following side effects, some of which may persist:
- low blood potassium which can affect kidney and heart functions.
- impaired glucose tolerance
- erectile dysfunction
Patients taking thiazide diuretics should have regular blood and urine tests in order to monitor blood sugar and potassium levels.
Patients aged 80 years or over may be given indapamide (Lozol), a special type of thiazide diuretic which helps reduce death from stroke, heart failure and some other cardiovascular diseases.
Beta-blockers were once very widely used for the treatment of hypertension. Because they have more potential side effects than other current hypertensive drugs, they tend to be used today when other treatments have not worked.
They slow the heart rate as well as reducing the force of the heart, resulting in a drop in blood pressure.
Beta-blockers may have the following side effects:
- cold hands and feet
- slow heartbeat
The side effects below are also possible, but less common:
- disturbed sleep
- erectile dysfunction
5) Renin inhibitors
Aliskiren (Tekturna, Rasilez) reduces renin production. Renin is an enzyme produced in the kidneys. Renin is involved in the production of a substance in the body called angiotensin I. Angiotensin I is converted into the hormone angiotensin II, which narrows blood vessels.
Aliskiren blocks the production of angiotensin I so that levels of both angiotensin I and angiotensin II fall. This causes widening of the blood vessels, resulting in a drop in blood pressure. As it is a relatively new medication its use and dosages for patients with hypertension are still being determined.
Aliskiren may have the following side effects:
- flu-like symptoms
Be sure to read the packaging of any medication to check for interactions with other drugs.
Managing the diet can be effective way of both preventing and treating high blood pressure.
This means eating plenty of fruits and vegetables, good quality unrefined carbohydrates, vegetable oils, and omega oils. If you eat animal products make sure all the fat is trimmed and avoid processed meats.
Lowering salt intake
Studies have shown that even a moderate reduction in salt, or sodium, intake can lower blood pressure levels by 2 to 8 mmHg.
A study found that most Americans who are diagnosed with hypertension still consume more than the recommended levels of salt.
Study leader, Umed Ajani, an epidemiologist with the National Center for Chronic Disease Prevention and Promotion, said:
“Perhaps the most striking finding is that no difference in sodium intake was observed between those who received advice and those who did not.”
A report published in March, 2009 by the Centers for Disease Control and Prevention (CDC) suggests that 7 in every 10 adult Americans should limit their sodium intake to 1,500 mg a day. The report estimated that 145 million Americans have one of three risk factors for hypertension. This is equal to roughly 70 percent of the adult population.
The AHA provide a useful table that lists common measurements of salt and their mg equivalents.
The DASH diet
The NIH designed a diet to control blood pressure called the DASH diet. It is also recommended by the AHA.
This diet is based on an eating plan that focuses on fruits, vegetables, nuts, seeds, beans, and low-fat dairy products.
Click here for a table advising the proportions of each food type to include for people wanting to follow the DASH diet.
Some studies indicate that consuming alcohol helps lower blood pressure, while others report the opposite.
In very small amounts, alcohol may lower blood pressure. But if you drink too much, even moderate amounts in some cases, blood pressure levels may increase.
People who drink more than moderate amounts of alcohol regularly will almost always experience elevated blood pressure levels.
There is a wide range of studies that report on whether caffeine has an impact on blood pressure. Many have conflicting conclusions but agree that moderating caffeine intake is advisable for people with high blood pressure.
Anyone whose blood pressure is 140/90 mmHg or more for a sustained period is said to have high blood pressure, or hypertension.
Blood pressure is usually divided into five categories:
- Hypotension, or low blood pressure
Systolic mmHg 90 or less, or
Diastolic mmHg 60 or less
Systolic mmHg 90-119, and
Diastolic mmHg 60-79
Systolic mmHg 120-139, or
Diastolic mmHg 80-89
- Stage 1 Hypertension
Systolic mmHg 140-159, or
Diastolic mmHg 90-99
- Stage 2 Hypertension
Systolic mmHg over 160, or
Diastolic mmHg over 100
People measure two types of blood pressure:
- Systolic pressure: This is the blood pressure when the heart contracts.
- Diastolic pressure: This is the blood pressure between heartbeats.
If you are told that your blood pressure is 120/80 mmHg, it means you have a systolic pressure of 120 mmHg and a diastolic pressure of 80 mmHg.
Most lay people have seen this device. It consists of an inflatable cuff that is wrapped around the upper arm. When the cuff is inflated it restricts the blood flow. A mercury or mechanical manometer measures the pressure.
A manual sphygmomanometer is often used together with a stethoscope.
With a digital sphygmomanometer all measurements are carried out with electrical sensors.
With advances in new wearable technology, people can now keep track of their blood pressure at home. You can read our review of the best home blood pressure monitors currently available to buy.
One blood pressure reading is not enough to diagnose hypertension in a patient. People’s blood pressure can vary during the day, a visit to the doctor may spike the reading because the patient is anxious or stressed, having just eaten may also temporarily affect blood pressure readings.
As the definition of hypertension is defined as “repeatedly elevated blood pressure” the primary care physician will have to take several readings over a set period. This may require three separate measurements one week apart – often the monitoring goes on for much longer before a diagnosis is confirmed.
On some rare occasions, if the blood pressure is extremely high, or end-organ damage is present, diagnosis may be made immediately so that treatment can start promptly. End-organ damage generally refers to damage to major organs fed by the circulatory system, such as the heart, kidneys, brain or eyes.
Kidney disorder: If the patient has a urinary tract infection, urinates frequently, or reports pain down the side of the abdomen, they could be signs and symptoms of a kidney disorder.
If the doctor places the stethoscope on the side of the abdomen and hears the sound of a rush of blood, it could be a sign of stenosis. This is a narrowing of an artery supplying the kidney.
Additional tests for high blood pressure
The doctor may also order the following tests to aid in diagnosis of high blood pressure:
Urine and blood tests: Underlying causes might be due to cholesterol, high potassium levels, blood sugar, infection, kidney malfunction, etc. Protein or blood in urine may indicate kidney damage. High glucose in the blood may indicate diabetes.
Exercise stress test: More commonly used for patients with borderline hypertension. This usually involves pedaling a stationary bicycle or walking on a treadmill. The stress test assesses how the body’s cardiovascular system responds to increased physical activity. If the patient has hypertension this data is important to know before the exercise test starts. The test monitors the electrical activity of the heart, as well as the patient’s blood pressure during exercise. An exercise stress test sometimes reveals problems that are not apparent when the body is resting. Imaging scans of the heart’s blood supply might be done at the same time.
Electrocardiogram (ECG): This tests the heart’s electrical activity. This test is more commonly used for patients at high risk of heart problems, such as hypertension and elevated cholesterol levels. The initial ECG is called a baseline. Subsequent ECGs may be compared with the baseline to reveal changes which may point to coronary artery disease or thickening of the heart wall.
Holter monitoring: The patient carries an ECG portable device that is attached to electrodes on their chest for about 24 hours.
Echocardiogram: This device uses ultrasound waves which show the heart in motion. The doctor will be able to detect problems, such as thickening of the heart wall, defective heart valves, blood clots, and excessive fluid around the heart.