Arterial thrombosis

About arterial thrombosis

Arterial thrombosis is a blood clot that develops in an artery. It’s dangerous as it can obstruct or stop the flow of blood to major organs, such as the heart or brain.

If a blood clot narrows one or more of the arteries leading to the heart, muscle pain known as angina can occur.

If a blood clot blocks the arteries leading to part of the heart muscle, it will cause a heart attack. If it blocks an artery in the brain, it will cause a stroke.

Symptoms therefore depend on where the blood clot has formed.

Find out more about the symptoms of arterial thrombosis

Who’s at risk of arterial thrombosis?

Most cases of arterial thrombosis are caused when a process called atherosclerosis damages an artery.

Fatty deposits build up on the walls of the arteries and cause them to harden and narrow.

Find out more about the causes and risk factors for developing arterial thrombosis

Treating arterial thrombosis

There are two main types of treatment for arterial thrombosis.

Medication

Medication can help dissolve clots and restore the flow of the blood to the brain or heart.

Surgery

Surgery involves a surgeon accessing the affected artery. They will either:

• unblock it
• re-route the blood flow via another blood vessel
• “graft” the blood vessel to travel around, or past, the section that’s blocked

Find out more about the treatment of arterial thrombosis

Preventing arterial thrombosis

If you’ve had a blood clot in an artery, you may need to take medication to prevent it from happening again.

It’s also vital that you live a healthy lifestyle. This includes:

• stopping smoking (if you smoke)
• doing some physical activity
• reducing the amount of salt and saturated fat that you eat

Find out more about preventing arterial thrombosis

Symptoms of arterial thrombosis

Depending on where the clot is in your body, a bloodclot in an artery (arterial thrombosis) can cause:

• angina
• heart attack
• stroke
• peripheral vascular disease

Find out about each of these below.

Heart attack

A heart attack can happen when a blood clot completely blocks an artery that pumps blood to your heart muscle.

You may experience:

• a crushing central chest pain or mild chest discomfort
• shortness of breath
• a clammy, sweaty and grey complexion
• dizziness
• nausea and vomiting

If you suspect you or someone you know is having a heart attack, dial 999 immediately. It’s important that you don’t wait and do treat these symptoms as an emergency.

Find out more about the symptoms of a heart attack

Stroke

Arterial thrombosis can cause a stroke if a blood clot is blocking an artery that supplies blood to your brain.

The symptoms of a stroke can come on suddenly and may include:

• numbness or weakness down one side, ranging in severity from weakness in your hand to complete paralysis of the whole side of your body
• weakness in your face, which can make you drool saliva
• dizziness
• difficulty talking and understanding what others are saying
• problems with balance and co-ordination
• difficulty swallowing

If you suspect that you or someone else is having a stroke, dial 999 immediately. It’s important that you don’t wait and do treat these symptoms as an emergency.

Further information on a stroke

Peripheral vascular disease

If you have a narrowing of an artery in one or both of your legs (peripheral vascular disease) you may:

• be more susceptible to developing a clot
• have pain when exercising, usually in the lower half of your legs
• have pain that may affect both legs, but develops in one leg before the other
• have pale, cold skin and numbness in one of your legs

Peripheral vascular disease can also cause other problems such as impotence (erectile dysfunction).

If you have any of these symptoms, it’s important to talk to your GP.

If one of your legs is a very different colour from the other, and you have other symptoms, you should treat this as an emergency and call 999.

Causes of arterial thrombosis

Arterial thrombosis occurs when a blood clot forms within an artery, slowing or stopping the flow of blood.

How it happens

Your blood contains cells called platelets and proteins (clotting factors). Together they make up the blood-clotting mechanism.

When a blood vessel is cut, the platelets and clotting factors in your blood mesh together to form a solid clot at the site of the wound. This clot acts as a plug to stop the wound from bleeding.

Normally, the blood-clotting mechanism is triggered when a blood vessel is damaged and bleeds, such as when you cut yourself. However, the blood may sometimes begin to clot even when a blood vessel has not been damaged.

If this happens, a blood clot can form within a vein or artery (thrombosis).

What causes it to happen

Most cases of arterial thrombosis are caused when an artery is damaged by atherosclerosis.

Fatty deposits build up on the walls of the arteries and cause them to harden and narrow. The risk factors for a blood clot in an artery include:

• eating a high-fat diet
• smoking
• alcohol misuse
• obesity
• lack of exercise
• diabetes (both type 1 diabetes and type 2 diabetes)
• high blood pressure (hypertension)

Diagnosing arterial thrombosis

The tests used to diagnose blood clots in the arteries (arterial thrombosis) will depend on what medical condition the blood clot has triggered.

Electrocardiogram (ECG)

Suspected cases of unstable angina and heart attacks are diagnosed using an electrocardiogram (ECG).

Every time your heart beats, it produces tiny electrical signals that will show on paper. This allows your doctor to see how well your heart is functioning or if there are any areas not receiving blood as in a heart attack.

Find out more about having an ECG

Blood test

Blood may also be taken to measure levels of a protein called troponin. This is released when the heart muscle is damaged by a heart attack.

Find out more about blood tests

Scans

Suspected cases of stroke are diagnosed by producing a scan of the brain using a computed tomography (CT) scan or magnetic resonance imaging (MRI) scan.

Treating arterial thrombosis

There are two main types of treatment for a blood clot that develops in an artery (arterial thrombosis):

• medication
• surgery

Medication

Medication can help dissolve clots and restore the flow of the blood to the brain or heart.

Surgery

You may need a heart procedure if the blood clot is in an artery that supplies blood to your heart. 

Coronary angioplasty

A coronary angioplasty is the most common type of procedure for a heart attack. 

A hollow metal tube called a stent is inserted to widen the artery and stop it from blocking again. 

Find out more about having a coronary angioplasty 

Coronary artery bypass graft (CABG)

Occasionally, a coronary artery bypass graft (CABG) may be carried out after a heart attack. 

A blood vessel that is taken from another part of the body is used to bypass where the blockage is.

Find out more about having a CABG  

Carotid endarterectomy

Another type of surgery for arterial thrombosis is called carotid endarterectomy, which you may have if you have had a blood clot in an artery in your neck (causing a stroke). 

The surgeon makes a cut in your neck to open up the artery and remove the fatty deposits. 

Preventing arterial thrombosis

It’s not possible to prevent blood clots altogether, but there are a number of ways to reduce the risks of developing a blood clot in an artery. 

Medication

If you’ve had blood clot in an artery before, you might need to take medication to prevent it from happening again. 

Medication can include:

• statins – used to lower your blood cholesterol levels 
• anticoagulant medicines- such as warfarin
• antiplatelet medicines – such as low-dose aspirin or angiotensin-converting enzyme (ACE) inhibitors (used to treat high blood pressure)

Lifestyle

In addition to medication, it’s vital that you look after your health and take steps to improve your lifestyle. 

Most cases of arterial thrombosis are associated with atherosclerosis (the ‘furring up’ of your arteries with fatty deposits). This can lead to a blood clot in an artery and cause a heart attack or stroke. 

Making healthy changes to your lifestyle can greatly reduce the effects of this condition, and others such a heart disease. 

Things you could do include:

• stopping smoking (if you smoke)
• reduce your alcohol intake to recommended limits
• reduce salt intake
• eat at least 5 portions of fruit and vegetables and 2 portions of fish per week (1 oily)
• do a minimum of 30 minutes of moderate exercise such as walking or cycling at least 5 times a week