Causes And Symptoms Of Isolated Systolic Hypertension

Introduction

Hypertension is the diagnosis given for high blood pressure. The condition known as isolated systolic hypertension occurs when blood pressure is taken and only the systolic (upper) reading is high, above 130 millimetres of mercury (mmHg), and the normal diastolic (lower) blood pressure reading is less than 90 mmHg. A normal blood pressure is less than 120 mmHg (systolic) and 80 mmHg (diastolic). 

The heart pumps blood around the body, and the systolic blood pressure is measured as the force of blood through the blood vessels as the heart beats. Whereas the diastolic measurement refers to the amount of pressure in the arteries as the heart is relaxing.¹ A continuously high pressure in the blood vessels is known as hypertension, sometimes referred to as high or increased blood pressure.

The blood vessels transport blood from the heart to every area of the body. The heart pumps blood into the vessels with each heartbeat. When blood is pumped by the heart, it presses on the walls of blood vessels, or arteries, creating blood pressure. High blood pressure increases the risk of heart, brain, kidney disease or injury.

Hypertension is a leading cause of premature death across the world. Almost a billion people, or one in four men and one in five women, have high blood pressure. Populations in low and middle-income nations have two-thirds of cases, and the burden of hypertension is severe. This is partly associated with an increase in risk factors in recent decades.²

Isolated systolic hypertension causes

Arteries lose their elasticity and stiffness with age and they are no longer able to expand or contract as they once did. Systolic blood pressure and pulse pressure rise and as a result of decreased elasticity, the diastolic blood pressure decreases.¹ 

Causes of isolated systolic hypertension include:³

• Artery rigidity
• Hyperthyroidism (overactive thyroid gland)
• Diabetes
• Heart valve dysfunction
• Being overweight 

Blood pressure is controlled by the volume of blood pumped by the heart around the body and the resistance to blood flow in the blood vessels. Blood pressure rises with the volume of blood that the heart pumps and the narrower the arteries. There are two forms of hypertension:⁴

• Essential hypertension or primary hypertension
• Secondary hypertension

Primary hypertension or essential hypertension

Primary hypertension is multifactorial and lacks a specific cause. It may be referred to as essential or idiopathic hypertension. Anything over 120/80 mmHg is usually considered above normal blood pressure. An indication that the arteries' internal pressure is higher than it ought to be. 

Primary hypertension harms the blood vessels and may lead to potentially fatal consequences such as:⁵

• Brain aneurysm
• Dementia
• Heart attack
• Heart breakdown
• Renal disease
• Malignant hypertension
• Stroke
• Loss of vision 

Essential hypertension causes⁶

Essential hypertension is identified by an absence of cause. However, there are a number of risk factors that increase the likelihood of the disease.

• Being overweight

Obesity can increase the risk of high blood pressure, placing more strain on the heart.

• Genetics

A family history of essential hypertension can increase familial susceptibility to this disease. There are fifty genes associated with hypertension.

• Age 

Age-related factors increase the risk of essential hypertension, including renal (kidney) microvascular illness causing hardening of the arteries.

• Stress

Hypertension is believed to be associated with chronic, or long-term, mental stress.

• Salt

Excessive salt (sodium) consumption, The average salt intake among adults is currently 8.4g a day well above the national guidance.7 The body retains more water when exposed to salt, which raises blood pressure by increasing blood volume.

• Renin 

Renin is an enzyme, a component of the body’s renin-angiotensin system that regulates arterial blood pressure and is related to both essential hypertension and hypertension. People with elevated or decreased renin levels are susceptible to hypertension. 

Secondary hypertension

High blood pressure with a specific cause is known as secondary hypertension. Due to the high prevalence of hypertension, it’s not cost-effective nor time-efficient to undertake routine tests. 

In some patient groups, it’s important to determine the cause and pathophysiology of secondary hypertension, to direct treatment plans, potentially cure hypertension, and stop the need for antihypertensive medication.

Causes of secondary hypertension⁸

Secondary hypertension can result from numerous medical problems including a number of kidney conditions such as:

• Diabetic sequelae (diabetic nephropathy) - damage to the kidneys' filtering function caused by diabetes
• Renal polycystic disease - A hereditary disorder, causes renal cysts and impacts renal function and blood pressure
• Glomerular disease - the kidneys use microscopic filters called glomeruli to filter out waste and salt. The glomerular disease causes these filters to enlarge. Blood pressure may rise as a result.
• Hypertension related to the kidneys - one or both of the kidney-directed arteries has narrowed (stenosis), which results in high blood pressure. 

The fatty deposits known as atherosclerosis, can harm coronary arteries and are frequently the cause of renal arterial hypertension. 

Symptoms of secondary hypertension⁹

Secondary hypertension may occur as a result of another health condition. It may be caused by disease of the arteries, heart, and endocrine system or kidneys. Taking one or two medicines may not be enough to control high blood pressure. 

Some illnesses may cause secondary hypertension such as these:

1. Pheochromocytoma: sweating, elevated heart rate or force, headaches, and anxiety
2. Cushing's syndrome: Gaining weight, becoming weaker, experiencing irregular body hair growth or, in people assigned female at birth, ceasing to menstruate, and having purple striations (lines) on the skin of the abdomen
3. Thyroid: weariness, gaining or losing weight, and sensitivity to heat or cold
4. Primary aldosteronism or ‘Conn's syndrome’: weakness caused by low potassium levels in the body
5. Obstructive sleep apnoea: Pauses in breath while sleeping, sleeping in the day 

Signs and symptoms of isolated systolic hypertension

Even when blood pressure rises to dangerously high levels, the majority of people with high blood pressure do not exhibit any symptoms. A small number of people may have: 

• Headaches
• Shortness of breath
• Nosebleeds

These symptoms are not common. Some signs indicate that isolated systolic hypertension is more symptomatic. The following symptoms may indicate isolated systolic hypertension: ¹⁰

• Feeling lightheaded or dizzy
• Headache
• Snoring or sleep apnoea
• Shortness of breath
• Nausea
• Leg swelling
• Confusion

Summary

Remember that early discovery of hypertension is essential for controlling the problem, even if there are no symptoms. This may involve being self-aware of any changes or new symptoms and planning frequent check-ups with the doctor.