Blood pressure is a key indicator of your health. This is why it is checked at every visit with a healthcare professional. Understanding this measurement will help you make sense of both your blood pressure and your healthcare professional’s advice. This article series will explain what blood pressure is, how to correctly measure it, and what to do when it is high.

WHAT IS HYPERTENSION?

Hypertension, commonly known as “high blood pressure”, is the condition of having a resting blood pressure measurement that is persistently higher than normal. Note the emphasis on resting blood pressure, and the long-term persistence of this elevation in blood pressure. This is different from having brief, temporary increases in blood pressure when you feel anxious or performing exercise that normalize afterwards. 

Having a persistently high resting blood pressure over many years can cause progressive damage to the heart and blood vessels throughout the body. This increases the risk of experiencing a stroke, heart attack, heart failure, and many other health complications that can cause disability or death. 

High blood pressure affects half of all adults in Australia and is the leading contributor to premature death worldwide, accounting for 13% of deaths globally each year. High blood pressure does not cause symptoms in most people, so a large proportion of these people do not know that they have it. The following table illustrates the different stages of high blood pressure

Category	Systolic Blood Pressure(mm Hg)	Diastolic Blood Pressure(mm Hg)
Normal	Less than 120	Less than 80
Elevated	120-129	Less than 80
High Blood Pressure, Stage 1	130-139	80-89
High Blood Pressure, Stage 2	Higher than 140	Higher than 90

High blood pressure can have many different causes, which we will discuss in further detail in a future article. These include things like genetics, smoking and alcohol use, overweight and obesity, physical inactivity, medications, and diet quality. Other underlying medical conditions like sleep apnea and kidney disease can also contribute to high blood pressure.

Physical activity produces a temporary increase in blood pressure, with more vigorous activities usually creating a higher increase. This is especially true with lifting weights. Holding your breath and exerting yourself against a resistance causes a large momentary spike in pressure. It does not increase your long-term resting blood pressure, which means lifting weights does not cause hypertension. In fact, the brief variations of blood pressure during lifting weights provide a useful stress to the cardiovascular system, and can lower resting blood pressure over time. This is an adaptation that is good for us, and means that even people with hypertension can benefit from strength training.

FACTORS THAT CAUSES HIGH BLOOD PRESSURE

• Body weight and body fat
• Physical activity habits
• Diet quality
• Sleep quality
• Drugs & medicines that increase blood pressure
• Medical conditions that increase blood pressure
• Age and Genetics

Body Weight And Body Fat

Body fat has a powerful effect on blood pressure — especially fat accumulated in the belly. Excess body fat releases hormones that activate the nervous system and make blood vessels squeeze tighter, while also increasing the amount of salt and water retained by the kidneys. These changes all result in higher blood pressure. One easy method to check for excess body fat is using a waist measurement.

Weight loss is one of the most effective ways to lower blood pressure. A sustained weight loss of just 5–10% of body weight can significantly lower blood pressure. 

A rough rule of thumb is that every 0.5kg of weight lost can lower blood pressure by about 1 point. However, there is variation in how people’s blood pressure changes with weight loss and even with successful weight loss, some people may need additional strategies to keep their blood pressure controlled over the long term. 

Aiming for a waist circumference goal is often more useful than a specific body weight. 

Our recommended waist circumference limits are as follows (see footnote for demographic caveats):

Male Waist Circumference	Health Risk	Female Waist Circumference
Less than 94 cm	No Increased Health Risk	80 cm
94-101 cm	Increased Health Risk	81-88 cm
102 cm	Significantly Increased Health Risk	88 cm

*These waist circumference values are for individuals in North America, Europe, or who are of European or African descent, and are independent of height. For those of Asian descent, subtract 7 cm from each value.

Physical Activity

Increasing physical activity decreases blood vessel stiffness, has beneficial effects on levels of circulating hormones and inflammation, and results in better regulation of appetite to maintain weight loss.

Current Physical Activity Guidelines recommend certain amounts of strength training and aerobic activity each week. Less than one-quarter of AUS adults currently meet these guidelines. Physical inactivity is one of the major contributors to high blood pressure and premature death worldwide, so this is an important focus for improving health.

The 2018 Physical Activity Guidelines for Americans recommend the following targets:150 to 300 minutes per week of moderate-intensity aerobic physical activity, OR;75 to 150 minutes per week of vigorous-intensity aerobic physical activity, AND;Strength training of moderate or greater intensity involving all major muscle groups on 2 or more days per week.

Performing both strength training and aerobic exercise has a greater effect on lowering blood pressure than performing either one by itself. Combining these forms of exercise can lower blood pressure to a similar degree as commonly used medicines.

Any increase in physical activity from a sedentary lifestyle will help, and these benefits increase further the more activity you do. Even if meeting these recommendations is difficult, the more you exercise, the greater the benefits to your health. 

Nutrition

Certain diets can impact blood volume and how tightly our blood vessels squeeze, in addition to their effects on body weight and body fat. As a result, food choices can improve blood pressure whether or not weight loss occurs.

Table salt (sodium chloride) can increase blood pressure for some people when they eat high amounts of it. Lowering sodium intake, while also increasing potassium intake, generally improves health and reduces the risk of heart disease. 

The US Department of Agriculture recommends that adults consume 4,700 mg of potassium per day, and less than 2,300 mg of sodium per day. There can be exceptions to this sodium recommendation for hard-training and competitive athletes, but this does not apply to most people. Unfortunately, these kinds of milligram targets of sodium and potassium are often not helpful for communicating what foods people should actually eat.

Highly processed foods have several characteristics that make them problematic for people struggling with their blood pressure. They are tasty, cheap, high in calories, not very filling, and often heavily salted. Replacing these kinds of foods with vegetables, fruits, legumes, nuts, whole grains, dairy products, and lean sources of protein such as fish is an excellent strategy to lower sodium intake, increase potassium and fiber intake, and ultimately lower blood pressure.

The “DASH Diet” is one of the most well-established diets that consistently improves blood pressure in humans, regardless of whether or not they have high blood pressure, and regardless whether weight loss occurs. However, there are many other diet patterns that can improve blood pressure and other aspects of health. 

Sleep

Blood pressure can rise if people are not sleeping enough, or if their sleep is of poor quality. This happens due to the effects of insufficient sleep on the heart and nervous system. People differ in the amount of sleep that they need for health; this also changes across the lifespan, with babies and young children generally needing more sleep than adults. For adults, targeting approximately 7–7.5 hours of sleep per night on a regular basis is a good starting recommendation.

In addition to sleeping long enough, ensuring quality sleep is also important. Bedtime habits to improve sleep quality are known as “sleep hygiene,” although this subject is beyond what we will cover here. We do want to address a common condition that causes high blood pressure called Obstructive Sleep Apnea. 

Obstructive Sleep Apnea, or just sleep apnea, is a disorder where people periodically stop breathing in their sleep without knowing it. Sleep apnea can also cause fatigue, morning headaches, heart and lung problems, and low testosterone. Men are at higher risk than women, as are those who snore, who are older, or who have excess body fat, but people without these risk factors can still have the condition. Treating sleep apnea improves blood pressure, and many patients can reduce their need for blood pressure-lowering medicines. 

Other Medical Conditions, Age, And Genetics

High blood pressure often occurs alongside other illnesses and conditions, which can compound the problem. These include, but are not limited to:

• Kidney disease, which is a very general term. Because kidneys are intimately associated with blood pressure management, compromised kidney function often affects it.
• Hormone disorders, especially those involving aldosterone. Not everyone needs their aldosterone levels checked, but there is a case to be made for broader testing of those with hypertension. 
• Pregnancy can lead to changes in blood pressure and becoming pregnant while hypertensive increases risks of complications to the mother and child. 

When high blood pressure is diagnosed in young people, or is resistant to treatment with multiple medications, some of these additional factors may need to be addressed. All these situations require diagnosis and care from a physician.

As people get older, they often decrease their level of physical activity. This causes loss of muscle mass, and gain of body fat. Further, blood vessels gradually stiffen with age. While we cannot modify our age to improve blood pressure, all the strategies we’ve discussed apply. Exercise can improve this stiffness, and making the diet substitutions described above can promote blood vessel relaxation.

About 30 to 50 percent of the variation in blood pressure is explained by people’s genes. People with genetically high blood pressure are typically unable to get it fully controlled through diet and exercise alone. This is not their fault, nor is it due to a lack of effort or willpower – it simply reflects the genes they inherited. This does not mean that people with genetic contributors to high blood pressure should not make the same kinds of lifestyle changes we have discussed above, but rather that these efforts may not be enough to get them all the way down to a healthy resting blood pressure. Medications are particularly helpful in these situations.

Drugs And Medicines

The use of alcohol, tobacco products, and other drugs can all influence blood pressure for the worse. Reducing or stopping use of these products can result in significant improvements in blood pressure and overall health, but quitting can be very challenging for many individuals. This is an entire topic unto itself, and we cannot do it justice here. Specific treatments are available to help increase the odds of successfully quitting tobacco and alcohol and seeking professional help increases the chance of success.

Similarly, lots of medicines can cause increases in blood pressure. Examples of these are listed below:

• Stimulants (such as those used for attention deficit disorder or for sports performance)
• Non-steroidal anti-inflammatory drugs (NSAIDs like Ibuprofen or Naproxen, often used to treat pain)
• Oral birth control pills
• Anabolic steroids, erythropoietin (EPO)
• Supplements, herbals, and other substances commonly used by athletes may contain ingredients or contaminants that cause high blood pressure

CONCLUSION

We can only speak in generalities about managing blood pressure because of the variability between people and the complexities of the topic. We are complex organisms and treatment decisions require taking a broad look at the person and considering the multiple contributing factors at play. However, there are some useful principles to keep in mind.

1. High blood pressure is a serious medical condition that is one of the leading causes of death and illness across the globe. It should be diagnosed and treated. Blood pressure is one of the few, regular medical screenings we recommend for all people. 
2. There are multiple lifestyle factors that we can modify to improve blood pressure. These include meeting the physical activity guidelines for both strength and aerobic exercise, decreasing waist measurements to target ranges, improving diet quality as described above, and getting sufficient high-quality sleep. These are important and powerful interventions that are appropriate for almost everyone, even if the implementation will vary between people. Exercise and dietary changes can lower blood pressure by as much as medications, especially for people that are currently inactive.
3. Even with excellent lifestyle habits, some people will still have persistently high blood pressure due to genetics or other undiagnosed medical conditions like obstructive sleep apnea. If no clear causes for high blood pressure are found, this is often a situation where blood pressure-lowering medicines are necessary.
4. There are numerous medicines available to lower blood pressure. While many people have a reluctance to take medicines, they can provide real benefit, especially when used alongside lifestyle modifications. Using very low doses of multiple medicines can be an excellent way to achieve the goal blood pressure, with fewer risks of side effects than using high doses of a single medicine.

With the background provided here, you hopefully have more information to determine if you are at risk for this condition and whether you should inquire with your physician. You also have some ideas about the treatments available. Even if you are unsure if you have high blood pressure, making lifestyle adjustments, particularly increasing how much you exercise, is likely an excellent course of action. Be active