High Blood Pressure Causes

What is considered high blood pressure?

The force exerted by the circulating blood in our body against the wall of the major blood vessels and arteries is called Blood Pressure (BP).¹ The blood pressure is recorded as two numbers:²

• The first number (systolic blood pressure) -indicates how much pressure your blood is exerting against artery walls when the heart beats.
• The second number ( diastolic blood pressure) reflects how much pressure your blood is exerting against the artery wall when the heart is resting between beats.

Hypertension is elevated blood pressure in more than the normal range. It’s diagnosed when the repeated measurement of systolic blood pressure is ≥140 mmHg and diastolic blood pressure is ≥90 mmHg for a couple of weeks.³

Symptoms

Hypertension (high blood pressure) is mostly without symptoms( silent Killer), people with hypertension will experience symptoms include:⁴

• Nervousness
• Sweating 
• Difficulty sleeping 
• Facial flashing 

Other symptoms:⁵

• Chest pain 
• Headache 
• Shortness of breath
• Nosebleeds
• Blurred vision

Causes

Hypertension is a complex disorder where both environmental and genetic factors play a role in causing it. Lifestyle, stress, excess salt and cholesterol intake, being overweight, age, smoking, genetic predisposition, and chronic disease all contribute to causing hypertension.

Stress

High stress is highly associated with hypertension. It’s an independent risk factor for hypertension.⁶

Chronic (constant) stress causes hypertension because our body responds to that stress by releasing adrenaline and cortisol (stress hormones) which constrict the blood vessels and increase heart rate, resulting in high blood pressure.⁷

Being overweight

Excess weight gain, especially when it is associated with high adipose tissue, is a major cause of hypertension. In obesity hypertension, there is an abnormal kidney function that produces mediators that act to increase blood pressure by:⁸

• Activation of the sympathetic nervous system, which leads to increased systolic blood pressure.
• Physical compression of the kidney by fat around the kidney.
• Activation of renin–angiotensin -aldosterone system, which leads to the narrowing of blood vessels that increases diastolic blood pressure and results in hypertension.

Excess salt/cholesterol intake

Salt is known to be a white killer. Extensive sodium intake isdefined by the World Health Organization as more than 2g of sodium or more than 5g of sodium chloride per day. Excess salt intake leads to increase systolic blood pressure and heart rate, which results in hypertension. The mechanism is by:⁹

• Water retention, which leads to  increased cardiac output.
• Increased systemic peripheral resistance resulting in  increased diastolic blood pressure.
• Endothelial dysfunction 
• Change of structure and of the large elastic artery.

Cholesterol intake is associated with an increased risk of hypertension.¹⁰ Excess cholesterol levels lead to cholesterol deposition in the blood vessels, which narrows the blood vessels and increases diastolic blood pressure leading to hypertension.

Smoking

Cigarette smoking causes acute blood pressure elevation. It’s associated with malignant hypertension. Nicotine in cigarettes acts as an adrenergic antagonist, which leads to the release of catecholamine and vasopressin (hormone act to prevent excessive urine and increase blood pressure).¹¹

Excessive alcohol

Chronic consumption of alcohol is associated with a high incidence of hypertension in men and women. The risk of alcohol consumption is higher in Black than in Asians or Caucasians. Reducing alcohol consumption promotes blood pressure reduction.¹²

Genetic predispositions

Genes play an important role in hypertension. Here are a few examples of gene defects that result in hypertension:¹³

• Deletion in gene encode (ANP) and (BNP), which overplayed cardiac fibrosis and led ventricular remodeling.
• Natriuretic peptide receptor A deficiency leading to increase blood pressure.

Some genes have a tendency to cause hypertension which explains the prevalence of  hypertension has been known to be higher among black than white people.¹⁴

Other chronic conditions

Many chronic diseases can cause hypertensionfor example:

• Kidney disease: chronic kidney disease results from chronic hypertension. A decreased glomerular filtration rate leads to increase cardiac output, which leads hypertension.¹⁵
• Liver disease: The most common chronic liver disease is Nonalcoholic fatty liver disease(NAFLD) which develops into advanced fibrosis, cirrhosis(an increase of fiberous tissue and destruction of liver cells), and ultimately cancer of liver cells. The prevalence of hypertension is higher in persons with ( NAFLD) because it induces renin-angiotensin system, systematic nervous system, and insulin resistance which are mechanisms that lead to developing hypertension.¹⁶
• Hormones imbalances: hormones are the chemical messengers that act to help monitor many of the processes in our body like breathing, reproduction and growth. An imbalance in these hormones can cause hypertension. Hormones like epinephrine, norepinephrine, and cortisol (work to produce the fight and flight response in stressful conditions), if  in levels, can lead to hypertension by inducing the activity of the sympathetic nervous system. Also, change in insulin levels causes diabetes, a risk factor for hypertension.¹⁷

Age

The incidence of hypertension increases with age. Because as we age, our blood vessels gradually lose some of their elastic quality, which leads to increased resistance to blood flow, resulting in increased diastolic blood pressure, leading to hypertension.¹⁸

Summary

Hypertension is increased blood pressure. Many factors contributing to it included environmental and genetic factors. The factors induce hypertension by either elevating systolic blood pressure  ( by activating renin-angiotensin two or the sympathetic nervous system ) or elevating diastolic blood pressure( by narrowing the blood vessels). The prevalence of hypertension increases with age. Other causes include smoking, alcohol, salt diets, stress, obesity, and chronic diseases.