Atherosclerosis is a potentially serious condition where arteries become clogged up by fatty substances known as plaques or atheroma.

The plaques cause affected arteries to harden and narrow, which can be dangerous as restricted blood flow can damage organs and stop them from functioning properly.

If a plaque ruptures, a blood clot may develop. This can lead to occlusion of the blood supply to the heart, triggering a heart attack, or it can block the blood supply to the brain, leading to a stroke.

Cardiovascular disease (CVD)

Atherosclerosis is a major risk factor for many conditions involving the flow of blood.

Collectively, these conditions are known as cardiovascular disease (CVD). Examples include:

  • peripheral arterial disease – where the blood supply of the limbs become blocked, causing muscle pain
  • coronary heart disease – the coronary arteries (the main arteries that supply your heart) become clogged with plaques
  • stroke – where the blood supply to the brain is interrupted
  • heart attack – where the blood supply to your heart is blocked

What causes atherosclerosis?

The reason arteries become clogged is not fully understood. Although there are factors that increases the risk for atherosclerosis:

  • smoking
  • a high-fat diet
  • lack of exercise
  • being overweight or obese
  • having either type 1 or type 2 diabetes
  • having high blood pressure (hypertension)
  • having high cholesterol

Symptoms of atherosclerosis 

Atherosclerosis is usually asymptomatic until blood flowbecomes significantly reduced, leading to cardiovascular disease (CVD).

The type of cardiovascular disease and its associated symptoms depends on where the blockage occurs.

Conditions caused by atherosclerosis include:

  • peripheral arterial disease
  • angina
  • aneurysm
  • heart attack
  • stroke

The conditions and their symptoms are described below.

Peripheral arterial disease

Peripheral arterial disease, also known as peripheral vascular disease, is a condition that occurs when there is a blockage in the arteries of the limbs (usually involving the lower limbs).

The most common symptom of peripheral arterial disease is pain in your legs. This is usually in one or both of your thighs, hips, or calves.

The pain can feel like a cramp, or a sensation of dullness or heaviness in the muscles of your legs. The pain usually comes and goes and is worse when doing exercise that uses your legs, such as walking or climbing stairs.

Other symptoms of peripheral arterial disease include:

  • weakness or numbness in the legs
  • having sores on the feet or legs that never heal
  • discoloration of the skin
  • hair loss on the legs or feet
  • thickening of toenails
  • erectile dysfunction, also known as impotence


Angina or chest pain is caused by a reduced blood supply to the heart.

The most common symptom of angina is a feeling of pain or discomfort in your chest. The pain can feel tight, dull or heavy, and usually passes within a few minutes.

The pain can spread from the chest to the left arm, neck, jaw and back. It usually follows a period of physical activity or emotional stress. In some cases, the pain can develop during cold weather or after eating a meal.

Some people with angina may also experience:

  • breathlessness
  • feeling sick
  • fatigue (feeling tired all the time)
  • dizziness
  • belching (burping)
  • restlessness

Angina symptoms are sometimes referred to as an angina attack.


Atherosclerosis may cause weakening of the blood vessel wall resulting into a bulge called an aneurysm.

If the aneurysm grows too large, there is a danger it will rupture, which can cause potentially fatal internal bleeding and organ damage.

An aneurysm can develop anywhere in the body, but the two most common types of aneurysm are:

  • a brain aneurysm (also known as a cerebral aneurysm), which develops inside the brain
  • an aortic aneurysm, which develops inside the aorta (a large blood vessel that runs down the abdomen and transports blood away from the heart)

If an aortic aneurysm ruptures, a sudden and severe pain in the middle or side of your abdomen will be experienced. In men, the pain can spread down into the scrotum (the sac containing the testicles).

Symptoms of a ruptured brain aneurysm usually begin with a sudden and severe headache, which has been described as like being hit on the head. If a ruptured aneurysm is suspected immediate medical attention is warranted.

Heart attack

If one of the plaques in the coronary arteries ruptures, it could create a blood clot. If the blood clot blocks the supply of blood to your heart, it will cause a heart attack.

Symptoms of a heart attack include:

  • chest pain – usually located in the centre of your chest and giving the sensation of pressure, tightness or squeezing
  • pain in other parts of the body that can feel as though it is travelling from your chest to your arms (usually the left arm, although both arms can be affected), jaw, neck, back and abdomen
  • an overwhelming sense of anxiety (similar to a panic attack)
  • shortness of breath
  • feeling sick
  • lightheadedness
  • coughing
  • vomiting
  • wheezing


Blood clots can also block the supply of blood to your brain, causing astroke.

The main symptoms of a stroke can be remembered by using the acronym FAST, which stands for:

  • Face – the face may have fallen on one side, the person may be unable to smile, or their mouth or eye may have drooped
  • Arms – because of a weakness or numbness of the arms, the person with a suspected stroke may not be able to raise both their arms and keep them raised
  • Speech – the person’s speech may be slurred
  • Time – it is time to dial 999 immediately if you see any of these signs or symptoms

Symptoms in the FAST test are successful in identifying about 90% of all strokes.

Other signs and symptoms may include:

  • dizziness
  • communication problems (difficulty talking and understanding what others are saying)
  • problems with balance and co-ordination
  • difficulty swallowing
  • severe headaches
  • numbness or weakness resulting in complete paralysis in one side of the body
  • loss of consciousness (in severe cases)

A transient ischaemic attack (TIA) is where the blood supply to the brain is temporarily interrupted, causing a “mini-stroke”.

The symptoms of a TIA are the same as those of a stroke, but they only last for between a few minutes and a few hours before disappearing completely.

However, a TIA should never be ignored as it is a serious warning sign that there is a problem with the blood supply to your brain.

Diagnosing atherosclerosis 

As atherosclerosis does not cause symptoms until cardiovascular disease occurs, those at risk of developing the condition should be tested.

Screening allows treatment to be given to reduce the risk of cardiovascular disease developing.

Screening is recommended for the following:

  • are over 40 years of age
  • are overweight or obese
  • are a smoker or have a history of heavy smoking
  • eat a high-fat diet
  • have high blood pressure (hypertension)
  • have type 1 or type 2 diabetes
  • have a family history of heart disease, high blood pressure or diabetes

There are several tests that assess your level of existing atherosclerosis and your risk of developing cardiovascular disease, including:

  • blood tests – to measure the amount of cholesterol in your blood and the amount of glucose, if you are diabetic
  • blood pressure tests
  • a measurement of your weight and waist size

Ankle-brachial index test will be done to compare the blood pressure in your ankle to the blood pressure in your arm. A difference between the two readings may suggest that atherosclerosis is restricting the blood supply to your legs and that you have peripheral arterial disease.

Further tests

If your risk of developing cardiovascular disease is high or you are experiencing symptoms of cardiovascular disease, further tests may be needed to confirm the level of atherosclerosis and locate any potential blockages in your arteries. These tests are explained below.


An electrocardiogram (ECG) measures the electrical activity of your heart. This test can measure how well your heart is functioning and can often detect the presence of heart disease.


An ultrasound scanner uses sound waves to build up a picture of the inside of your body. This can be used to measure your blood pressure at different points in your body. Any variation in pressure could point to the site of a blockage in your arteries. Ultrasound tests can also be used to study the larger arteries.


During an angiography you are injected with a special dye that can be seen on X-ray. The test is used to see how the blood flows through your body.

Computerised tomography scan

A computerised tomography (CT) scan takes a series of X-ray images and uses a computer to assemble them into a more detailed three-dimensional image. It can often detect narrowing or hardening in the larger arteries.


An ophthalmoscopy is a type of eye test where an instrument called an ophthalmoscope is used to examine the blood vessels in the back of your eye. The ophthalmoscope can sometimes detect hardening of the blood vessels in your retina (the retina is the light-sensitive layer at the back of the eye).


Treating atherosclerosis 

If you are at risk of developing a cardiovascular disease (CVD) as a result of atherosclerosis, you will be advised to change your lifestyle to reduce this risk.

Lifestyle changes include modifications in the diet and exercise.


There are several medications available to treat many of the underlying causes of atherosclerosis, such as a high cholesterol level and high blood pressure (hypertension).

Depending on individual circumstances, you may only need to take one medication, or you may need a combination of different medications.

High blood pressure (hypertension)

The most widely used medications for treating high blood pressure are outlined below.

Angiotensin-converting enzyme (ACE) inhibitors

Angiotensin-converting enzyme (ACE) inhibitors work by blocking the actions of some of the hormones that help regulate blood pressure.

ACE inhibitors reduce the amount of water in your blood as well as widening your arteries, both of which will lower your blood pressure.

ACE inhibitors are not suitable for:

  • pregnant or breastfeeding women
  • people with conditions that affect the blood supply to their kidneys
  • those with a history of heart disease

The side effects of ACE inhibitors include dizziness, tiredness and headaches.

If the side effects of ACE inhibitors become troublesome, angiotensin-2 receptor antagonists may be recommended. They work in a similar way to ACE inhibitors.

Calcium channel blockers

Calcium channel blockers work by relaxing the muscles of your artery walls, which causes your arteries to widen and lowers your blood pressure.

Calcium channel blockers are not recommended for people with a history of heart disease, liver disease or circulation problems.

Side effects include a flushed face, headaches, swollen ankles and dizziness.

Drinking grapefruit juice is avoided if you are taking calcium channel blockers because this can cause your blood pressure to fall.

Thiazide diuretics

Thiazide diuretics work by reducing the amount of water in the blood and widening the walls of your arteries.

They are not recommended for pregnant women or people with gout (a type of arthritis where crystals develop inside the joints).

Thiazide diuretics have been known to reduce the level of potassium in your blood, which can interfere with your heart and kidney functions. They can also raise the level of sugar in your blood, which could lead to diabetes.

You will probably be advised to have blood and urine tests every six months so that your potassium and blood sugar levels can be monitored.

A few men reported they could not get or maintain an erection while taking thiazide diuretics, although this side effect resolved once the medication was withdrawn.

High cholesterol levels


Statins are a type of medication used to lower blood cholesterol levels. Statins block the effects of an enzyme in your liver called HMG-CoA reductase, which is used to make cholesterol.

Statins sometimes have mild side effects, including constipation,diarrhoea and headaches.

Occasionally, statins can also cause muscle pain, weakness and tenderness. You should contact your GP if you experience these symptoms because your dosage may need to be adjusted.

If you have high blood cholesterol, you may need to take statins indefinitely.

Preventing blood clots

As many of the serious complications that arise from atherosclerosis are associated with blood clots, such as heart attack and stroke, you may be given medication to help reduce the risk of a blood clot developing.


Medications used to prevent blood clots developing are known as antiplatelets. Platelets are tiny particles in the blood that help it to clot. Antiplatelets work by reducing the “stickiness” of platelets.

A regimen with low-dose aspirin, a nonsteroidal antiinflammatory drug used as an analgesic, has blood-thinning properties.

If tests reveal a greater risk of developing a blood clot than usual, an additional antiplatelet medication called clopidogrel will be given. Clopidogrel can also be used if you are allergic to aspirin.


Surgery may be required if certain important blood vessels become narrowed. These are the:

  • coronary arteries, which supply blood to your heart (narrowing of your coronary arteries can trigger a heart attack)
  • carotid arteries, which supply blood to your brain (narrowing of your carotid arteries can trigger a stroke)

Coronary angioplasty

Coronary angioplasty is a type of surgery used to widen your coronary arteries.

A long, flexible plastic tube called a catheter is inserted into a blood vessel and a balloon attached to the catheter is inflated to widen the artery.

A small metal tube called a stent is often used to help keep the artery open.

Coronary artery bypass graft

A coronary artery bypass graft (CABG) can be used to treat narrowing of the coronary arteries. During a CABG, healthy blood vessel segment (graft) is taken from other parts of the body to bypass the blocked artery.

Segments of vein taken from your legs, arms and chest are used to create a new channel through which blood can be directed around the blocked part of the artery. This enables more blood to get through to the heart muscle.

Carotid arteries

Surgery is usually only recommended to widen the carotid arteries when previous symptoms related to a blocked blood supply has occured, such as a stroke or transient ischaemic attack (TIA).

Unlike the coronary arteries, preventative surgery on the carotid arteries is not usually recommended, except in cases where testing shows high levels of narrowing.

This is because studies have found that the benefits achieved in reducing the risk of a stroke in most people without any symptoms are outweighed by the risks associated with surgery.

Carotid endarterectomy

A carotid endarterectomy is the most commonly used method of widening the carotid artery (the main artery in your neck).

During the procedure, a cut is made into the narrowed part of the artery and the inner lining of the artery is removed, along with any plaque inside it.

Most surgeons sew a patch into the opening to widen this section of the artery. The patch may be taken from a vein in your thigh or it might be synthetic (man-made).

Using a patch can reduce your risk of having a stroke after the operation, as well as reducing the likelihood of restenosis (the artery becoming narrowed again).

Carotid angioplasty

Carotid angioplasty uses a catheter, a thin plastic tube with an inflatable balloon at one end, which is threaded through the femoral artery (main artery in the groin) and up to the carotid artery.

The catheter is guided through fluoroscopy using X-rays to construct an image.

The balloon is then inflated to around 5mm in diameter. This expands the artery, clearing the narrowing so blood is able to flow through it again.

Carotid angioplasty is a less invasive type of surgery than carotid endarterectomy, this will result in less postoperative pain and faster recovery time.

Extracranial to intracranial bypass

A new type of surgery used to treat blockage of the carotid artery is known as an extracranial to intracranial bypass.

A section of blood vessel found outside the skull is diverted and used to bypass the site of the blockage so that the blood supply to the brain can be restored.

Extracranial to intracranial bypass is still an evolving field of treatment and it is unclear how effective or safe it may be in the long term.

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