What is High Blood Pressure (Hypertension)?

At a Glance:

• Hypertension or high blood pressure is classified as any blood pressure of 135/85 mm Hg or above
• Hypertension is typically asymptomatic but may lead to serious complications and health problems such as heart attack, stroke, heart failure, kidney failure, dementia and eye damage
• There is no single identifiable cause of hypertension but a number of factors, including physical inactivity, age, sex, genetic predisposition, diet, being overweight or obese, smoking and stress may contribute to high blood pressure
• Men are more likely to develop high blood pressure before the age of 65
• Women are more likely to develop hypertension after the age of 65
• Overall, men are more likely to develop hypertension than women, with one in four men predisposed to develop the condition as opposed to one in five women
• Hypertension may be treated with a combination of lifestyle change and medication

What is Hypertension?

Whilst blood pressure may be high at some time of the day, such as during exercise or some other activity requiring physical exertion, this pressure should drop down to healthy levels once the activity has ceased. Blood pressure that remains high at all times is referred to as hypertension. 

Hypertension is classified as any blood pressure of 135/85mm Hg and over. It’s important to have regular blood pressure tests as hypertension is typically asymptomatic. Although there may be no outward symptoms, hypertension is one of the major risk factors for cardiopulmonary issues such as heart attack (myocardial infarction) and stroke.

What Causes High Blood Pressure?

There is no single identifiable cause of high blood pressure but rather a number of contributing causes, including:

1. Family History - you are more likely to have high blood pressure if you have a direct relative with high blood pressure 
2. Diet - a diet high in sodium may be a significant risk factor for hypertension. Sodium helps your body retain fluid, so excess sodium can cause excess fluid retention, increasing blood pressure. 
   
   Likewise, a diet without enough potassium may be a risk factor for hypertension, as potassium helps balance the amount of sodium stored in your cells. Without enough stored potassium your sodium levels may become too high leading to fluid retention and high blood pressure.
   
   A poor diet may be a risk factor for weight gain. Being overweight or obese is another significant risk factor for hypertension. 
3. Smoking - tobacco use (smoking or chewing) elevates your blood pressure immediately. Not only that, chemicals produced by smoking may damage the walls of your arteries causing narrowing and increasing the risk of heart disease
4. Alcohol Intake - heavy drinking may lead to heart damage and issues with blood pressure
5. Weight - being overweight or obese may lead to high blood pressure. As body mass increases, more pressure is required to pump blood. The greater the mass the more pressure required to pump blood
6. Physical Inactivity - people who are physically inactive typically have a higher heart rate and blood pressure than physically active people. Physically inactive people are also more likely to be overweight or obese, making the heart have to work harder to pump blood through excess mass
7. Stress - high levels of stress may increase blood pressure. Stress may lead to increased instances of alcohol intake, smoking and overeating
8. Age - high blood pressure becomes more common as you age. Hypertension is more common in men up until around the age of 64. Women are more likely to develop high blood pressure after the age of 65
9. Sex - men are slight more likely to develop hypertension. Around one in four men have high blood pressure as opposed to one in five women  
   
   For some people there is no identifiable cause or risk factor for hypertension. This is referred to as Primary Hypertension, a condition that typically develops slowly over time with no readily identifiable cause.

Hypertension may also be classified as Secondary Hypertension when it is a result of an underlying medical condition. Conditions and diseases that may lead to hypertension include:

1. Adrenal Gland Tumours
2. Anxiety
3. Depression
4. Congenital Blood Vessel Defect
5. Diabetes
6. Drug Use - such as amphetamines and cocaine
7. Kidney Problems
8. Medication - certain medications may affect blood pressure, such as birth control, some NSAIDs, some decongestants and some prescription drugs
9. Obstructive sleep apnea
10. Thyroid problems

Schedule an appointment with your GP to have your blood pressure tested. The fastest and easiest way to search for and book healthcare appointments online is through MyHealth1st.

Complications of Hypertension

Excess pressure on the walls of your blood vessels may cause damage to both blood vessels and the organs they supply. Potential complications of hypertension include: 

• Aneurysm - an aneurism forms when blood vessels weaken and bulge due to blood pressure. If the building blood vessel bursts if may be fatal
• Atherosclerosis - the hardening and thickening of blood vessels due to high blood pressure. Atherosclerosis may lead to a number of serious conditions including heart attack and stroke
• Cognitive and Memory Impairment - issues dealing with memory and cognition are more common in people with high blood pressure than those with normal blood pressure
• Dementia - damage to arteries in or leading to the brain may cause narrowing or blockages, limiting the amount of blood that can flow freely to the brain and deliver oxygen and other vital nutrients. This may result in a form of dementia known as vascular dementia. A stroke (see atherosclerosis above) may also lead to vascular dementia
• Eye Damage - hypertension may cause damage to the tiny blood vessels of the eye. Damage to the retina is referred to as retinopathy and may result in complete loss of vision. People living with diabetes who also have high blood pressure are most at risk of retinopathy.

Damage to the blood vessels may lead to a buildup of fluid in the eye. This is referred to as choroidopathy and may result in distorted or blurred vision or scarring in the eye.  

Blocked or significantly reduced blood flow in the eye due to damage to the arteries may damage the optic nerve. This is referred to as optic neuropathy and may lead to complete vision loss.

• Heart Failure - the higher the blood pressure the more the heart has to pump to maintain blood flow. As the heart continues to work harder than normal the walls of the heart, especially the left ventricle (the part of the heart that pumps). This is referred to as left ventricular hypertrophy.

To pump blood against the higher pressure in your vessels, the heart has to work harder. When the walls of the ventricle become too thick from overwork it may have difficulty pumping enough blood around your body to meet its needs. This is heart failure.

Atrial Fibrillation-this is the most common significant heart rhythm disturbance & is more common in hypertensive people.

• Kidney Damage - your kidneys filter fluid and waste from your blood, but if the arteries are damaged due to high blood pressure the kidneys may have a hard time performing this task effectively. This may cause dangerous levels of fluid and toxins to build up. This is referred to as kidney failure.

Damage to the arteries in the kidneys may also cause scarring. Kidney scarring, also known as glomerulosclerosis. The scarring makes it more difficult for the kidneys to do their job and may lead to kidney failure

• Metabolic Syndrome - a collection of related disorders that affect the body’s metabolism, such as high bad cholesterol and low good cholesterol , high blood pressure, high insulin levels and an expanded waist circumference. Metabolic syndrome makes a person more likely to develop diabetes, stroke of heart attack

Treatment for Hypertension

Treatment for hypertension may vary depending on the underlying cause and severity but may include medication for contributing diseases or conditions as well as lifestyle and diet change.

Medications that may be prescribed to help with hypertension vary due to cause and severity but may include:

• ACE Inhibitors - Angiotensin-converting enzyme (ACE) inhibitors block the creation of naturally occurring chemicals that cause blood vessels to narrow

• ARBs - Angiotensin II receptor blockers (ARBs) work similarly to ACE inhibitors but rather than blocking the creation of blood vessel narrowing chemicals, ARBs instead block the action of the chemicals 
• Calcium Channel Blockers - calcium channel blockers help relax blood vessels and some may also slow heart rate

• Diuretics - also referred to as thiazide diuretics or “water pills”, diuretics help your kidneys eliminate sodium and excess water thereby lowering blood volume and pressure. Thiazide diuretics are typically a first line prescription for hypertension

Additional, more specialised medications to treat high blood pressure may be used if a patient does not respond to the commonly prescribed drugs listed above. In some cases, medications for the treatment of anxiety and depression may be able to treat hypertension if the mental health condition is a significant underlying cause of the high blood pressure.

Lifestyle changes that may be recommended for the management of hypertension include:

• Eating a healthy diet with adequate levels of potassium and low sodium
• Quitting smoking
• Losing weight if you are overweight or obese
• Limiting alcohol intake
• Getting regular exercise or maintaining regular physical activity

Hypertension is sometimes referred to as a “silent disease” as in many cases there are no outward symptoms until there are serious complications. That’s why having your blood pressure regularly tested is so important.