Understanding high blood pressure

High blood pressure is one of the most common chronic diseases. As much as 25% of the adult population throughout the world have high blood pressure.

Hypertension, or high blood pressure, is defined as higher-than-normal pressure inside blood vessels such as arteries. The trouble with high blood pressure is it puts more stress on blood vessels, the heart and the kidneys, and leads to heart attacks, strokes and kidney disease.

Ninety percent of hypertension is classified as essential hypertension. Nobody knows what causes it. Hypertension is considered a “silent” disease. Most of the time, it causes no symptoms, although some people complain about headaches, muscle tension and a general feeling of unwellness.

The cardiovascular system includes the heart and blood vessels, such as arteries and veins. The average human body contains about five litres of blood, which contains oxygen and other nutrients that are delivered to all cells throughout the body. Blood also removes toxins and waste material from cells. Arteries carry oxygenated blood, rich in nutrients to cells and veins and carries unoxygenated blood away from cells.

The heart is the pump that pushes blood throughout the body. The average heart contracts at 72 beats per minute, about 100,000 times per day or 2.5 billion times in the average human’s lifetime. The average adult human body contains 100,000 kilometres, or 60,000 miles, of blood vessels if they were connected in one long chain. That is long enough to travel twice around the circumference of the earth.

The average normal blood pressure is 120/80 millimetres of elevation on a blood pressure cuff device. High blood pressure is defined as a blood pressure reading higher than 140 over 90.

Blood pressure can vary with many things—activity levels, exercise, stress, anxiety, salt intake, smoking, weight and other factors.

A blood pressure cuff is a simple device used to measure arterial pressure. The cuff is slipped around a bare arm just above the elbow at about heart level. A bulb inflates pressure around the cuff above the level of arterial pressure and is then slowly deflated to give an accurate reading of the pressure within the brachial artery. The higher, or top number, is called the systolic blood pressure. The lower, or second number, is considered the diastolic blood pressure. Both numbers are equally important.

The heart and blood vessels form a closed system of circulation. That means fluid or blood is conserved and is not lost when it is pumped throughout the body. The same fluid volume is always maintained unless there is blood loss. The heart is a strong muscle that forces blood through blood vessels to deliver oxygen and nutrients to cells and remove carbon dioxide and waste materials from cells.

When the heart contracts, blood is forced, under higher pressure, throughout the chain of blood vessels. That contraction phase in called systole and is the systolic blood pressure. When the heart relaxes, the closed chain of blood vessels still has blood and pressure in it. That relaxation phase is the diastole and is known as diastolic blood pressure.

If the systolic blood pressure is high, the first (or higher) reading is higher than 140. If the diastolic blood pressure is high, then the second reading is higher than 90.

Salt and sodium are involved in blood pressure and fluid regulation within blood vessels. They are also important for proper muscle and nerve function throughout the body. Sodium helps to maintain proper healthy blood pressure. The amount of sodium in the blood directs the flow of water from in and out of cells.

The concentration of sodium is maintained constantly by different hormones like renin, aldosterone and the movement of salt and water through the kidneys. If sodium is high in the blood, water loss will be conserved the kidneys to increase water supply to the blood. High salt and sodium contribute to rising pressure in the blood vessels.

The recommended dietary allowance (RDA) of salt is about one teaspoon or 5,000 milligrams per day. Salt is 40% sodium and 60% chloride, therefore, one teaspoon of salt equals about 2,000 milligrams of sodium.

The problem with salt is many people consume too much of it. The average Canadian adult consumes just under 10,000 milligrams of salt per day, or about the double the RDA. Salt is added and hidden in many processed and refined foods. It tastes good, but most are getting more than they need. This directly contributes to high blood pressure.

Other dietary and lifestyle factors that contribute to high blood pressure include a lack aerobic exercise and inactivity, a lack of nutrients, primarily including electrolytes such as calcium, magnesium and potassium, excess sugar and refined carbohydrates, increased consumption of alcohol, coffee and other caffeinated beverages, smoking and mental and emotional states.

The information provided in this article does not, and is not intended to, constitute medical advice. All information and content are for general information purposes only.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.