More on clogged arteries
What is furring of the arteries (or atherosclerosis)?
You may have heard the terms ‘hardened arteries’ or ‘furred arteries’ before, but have you ever wondered what they actually mean?
Cells need oxygen to survive. Blood vessels are flexible tubes, which deliver
these important substances around the body by carrying them in the blood.
Arteries are the main type of blood vessels, which carry blood rich in oxygen from the heart to the rest of the body. They are very muscular and can stretch like an elastic band.
Furring of the arteries (or atherosclerosis) is caused by the build-up of fatty
deposits, cholesterol, and waste products in the walls of the arteries. This buildup is called a fatty plaque. A fatty plaque can be dangerous because as it grows it causes narrowing of the blood vessels. Over time these vessels also lose their elasticity, and the amount of blood able to pass through the blood vessel reduces, and therefore the amount of oxygen getting to the cells is reduced. You can have more than one fatty plaque and these can occur anywhere in the body.
See how cholesterol clogs your arteries.
Why does this matter?
Furring of the arteries usually develops slowly, but it can develop quickly in some people. The build-up of a fatty plaque is a serious condition. Over time, the fatty plaques become larger and eventually the flow of blood through the arteries is restricted. Most people show no signs or symptoms at first and wrongly assume that they are ok and don’t need to change their lifestyle or seek help.
However, the first symptom you feel may be life threatening and can be fatal. It is usually during the later stages of the disease that complications and symptoms appear.
Symptoms begin when the blood supply becomes severely reduced. Blood
supplies oxygen to the whole body including the heart, brain, and kidneys. If the amount of blood able to pass through an artery is reduced, then the amount of oxygen supplying these organs will also be reduced. The lack of oxygen causes pain in that part of the body. Your body will not function as well and you will feel less able to go about your everyday activities. Read about the symptoms of plaque build-up here.
More seriously, these fatty plaques can suddenly break-up at any time and with no warning. The pieces can then block arteries and cause life changing events such as a heart attack, stroke, or even death. To watch a video of how this happens, click here.
Therefore preventative measures such as changes in lifestyle and taking
medication are very important to minimise the risk of these serious events
happening. You can learn about what you can do to help reduce your risk here.
Furring and clogging of the arteries can lead to serious complications. Clogging of the arteries is considered the most important underlying cause of strokes, heart attacks and other heart diseases. In fact, fatty plaque build-up is the main cause of heart disease — the number one killer worldwide.
What is happening in your arteries?
How does the process begin?
(endothelium) is damaged. The major cause of damage to the arteries includes: high levels of cholesterol and other fats in the blood, smoking, high blood pressure and diabetes.
There are two types of cholesterol known as good and bad cholesterol. To learn about the different types of cholesterol, click here. Bad cholesterol enters the damaged artery lining and undergoes a chemical change.
The damage to the vessel wall results in an inflammation response or a ‘call for help’. White blood cells answer this ‘distress call’ and try to clear the bad
cholesterol away by eating it. The white blood cells turn into fat filled ‘foam
cells’, so called because of their altered appearance. A build-up of foam cells in the vessel wall appears as a fatty streak and is often called ‘furring of the
arteries’. Watch this process here.
Fatty streak formation or furring of the arteries is the earliest stage of plaque
formation. These ‘fatty’ streaks are not actual streaks of fat that line the artery wall like dirty pipes, but are collections of fat-filled white blood
cells (or foam cells) in the artery wall itself. These fat-filled cells contain the bad cholesterol and give the fatty streaks their yellow appearance.
The fat-filled foam cells eventually die and this causes further inflammatory reactions that set-off the generation of new muscle cells. The new muscle cells move from the outer layers of the blood vessel into the middle layer to help form a fibrous capsule that covers the fatty streak. The new muscle cells help strengthen the fibrous capsule and make it less prone to breaking open. This fibrous capsule separates the fatty streak from the blood in the artery and together the fatty streak plus fibrous cap form a ‘fatty plaque’.
How do our arteries cope?
An artery is like an elastic band — in the early stages of the disease the artery is very stretchy and expands outwards to make room for the plaque build-up. This is called ‘remodelling’. After the artery or elastic band has been stretched to its limit, it becomes hard and inflexible and the artery cannot stretch any further. The fatty plaque then starts to grow into the vessel opening. This leads to narrowing of the arteries, which reduces blood flow to vital organs like your heart, and causes things like chest pains (angina) or cramps.
Hardening of the arteries
As shown in the animation , calcium builds-up between the muscular wall of the artery and outer portion of the fatty plaque. The process can begin early and speeds up as the disease progresses and fatty plaques become more complex. The build-up of calcium (or ‘calcification’) in the arteries also contributes to loss of elasticity and stiffening of the artery, this is known as ‘hardening of the arteries’.
What happens next?
Fatty plaques within the vessel wall are fragile and prone to rupture. If these
plaques rupture, a blood clot can form which can partially obstruct or completely block the blood vessel. You can see this process here .
Repeated ruptures of the fibrous cap separating the plaque from the blood
stream causes increased narrowing of the artery opening. It is a combination of this rupturing and healing process that leads to narrowing of the arteries, rather than plaque growth alone. However, this process is more common in people over 40 years old.
Obstruction, either at the site of rupture, or as a result of plaque debris sent
downstream, blocks adequate blood flow to cells downstream. Cells starved of an adequate blood supply are injured and die. This is what happens during a heart attack or stroke.
What can I do about my artery health?
It is important to lead a healthy lifestyle and take the appropriate treatment to
reduce your cholesterol levels. 20% or more of the cholesterol in your blood
comes from your diet and up to 80% is made by the body in the liver. Therefore eating healthily and exercising alone may not be enough, and this is why it is important to take your prescribed treatment on a regular basis.
