Peripheral arterial disease (PAD)
Peripheral arterial disease (PAD) is a common condition, in which a build-up of fatty deposits in the arteries restricts blood supply to leg muscles. It is also known as peripheral vascular disease (PVD).
Many people with PAD have no symptoms. However, some develop a painful ache in their legs when they walk, which usually disappears after a few minutes' rest. The medical term for this is "intermittent claudication".
When to see your GP
You should see your GP if you experience recurring leg pain when exercising.
PAD is usually diagnosed through a physical examination by your GP, and by comparing the blood pressure in your arm and your ankle.
A difference between the two may indicate PAD and is called the ankle brachial pressure index (ABPI).
What causes PAD?
PAD is a form of cardiovascular disease (CVD), meaning it affects the blood vessels.
It is usually caused by a build-up of fatty deposits in the walls of the leg arteries. The fatty deposits, called atheroma, are made up of cholesterol and other waste substances.
The build-up of atheroma on the walls of the arteries makes the arteries narrower and restricts blood flow to the legs. This process is called atherosclerosis.
Who is affected
Your risk of developing PAD increases as you get older. It's estimated that around one in every five people over the age of 60 are affected by the condition to some degree.
Men tend to develop the condition more often than women.
There are certain things that can increase your chances of developing PAD and other forms of CVD, including:
smoking – the most significant risk factor
type 1 diabetes and type 2 diabetes
high blood pressure
By tackling these risk factors, you may be able to reduce your chances of developing PAD and other types of CVD.
How PAD is treated
PAD is largely treated through lifestyle changes and medication.
Exercising regularly and stopping smoking, if you smoke, are the main lifestyle changes that can ease the symptoms of PAD and reduce the chances of the condition getting worse.
The underlying causes should also be treated, such as reducing high blood pressure and cholesterol, and diabetes. Medication, and in some cases surgery, can be used to improve the blood flow in your legs.
With treatment, most people's symptoms will remain relatively stable, and some people may experience an improvement in their pain.
If treatment is unsuccessful or you can't make appropriate lifestyle changes, there is a risk of potentially serious complications (see below).
While PAD is not immediately life-threatening, the process of atherosclerosis that causes it can lead to serious and potentially fatal problems.
Having PAD means you have a much higher risk of developing other serious forms of CVD, such as heart attack and stroke, because it is likely that blood vessels elsewhere in your body are also affected by atherosclerosis.
If the symptoms of PAD get worse, there is a risk that leg tissue will begin to die (known as gangrene). In severe cases, the lower leg may have to be amputated.
Symptoms of peripheral arterial disease
Many people with peripheral arterial disease (PAD) don't have any symptoms. However, you may feel painful aching in your leg muscles that is triggered by physical activity, such as walking or climbing stairs.
The pain, known as intermittent claudication, usually develops in your calves, but your hip, buttock or thigh muscles can be affected.
The pain can range from mild to severe, and will usually go away after a few minutes when you rest your legs.
Both legs are often affected at the same time, although the pain may be worse in one leg.
Other symptoms of PAD can include:
hair loss on your legs and feet
numbness or weakness in the legs
brittle, slow-growing toenails
ulcers (open sores) on your feet and legs, which don't heal
changing skin colour on your legs, such as turning pale or blue
in men, erectile dysfunction
the muscles in your legs shrinking (wasting)
The symptoms of PAD often develop slowly, over time. If your symptoms develop quickly, or get suddenly worse, it could be a sign of a serious problem requiring immediate treatment (see below).
When to seek medical advice
See your GP if you experience recurring episodes of leg pain after physical activity, especially if you smoke, or have a confirmed diagnosis of diabetes, high blood pressure and/or high cholesterol.
Many people mistakenly think recurring episodes of leg pain are part of growing older. This is not the case – there is no reason why an otherwise healthy person should experience leg pain.
When to seek urgent medical advice
Some symptoms may suggest that the supply of blood to your legs has become severely restricted, and you may need to see a doctor urgently. These include:
your symptoms getting suddenly worse
constant leg pain, even when resting
being unable to move the affected leg
a sudden loss of normal sensation in the affected leg, or a burning or prickling sensation
a difference in the colour and temperature of your legs
persistent ulcers on one or both legs
the muscles in your legs beginning to waste away
the skin on your toes or lower limbs turning red and then black and/or beginning to swell and produce foul-smelling pus, causing severe pain (gangrene)
If you experience any of the problems listed above, contact your GP as soon as possible. If this is not possible, phone 111 or your localout-of-hours service.
These symptoms could be a sign of a complication of PAD called critical limb ischemia (CLI), which requires urgent treatment.
Read more about the complications of PAD.
Causes of peripheral arterial disease
Peripheral arterial disease (PAD) is usually caused by a build-up of fatty deposits on the walls of the arteries inside the legs. The fatty deposits, called atheroma, are made up of cholesterol and other waste substances.
The build-up of atheroma on the walls of the arteries makes the arteries narrower and restricts the flow of blood to the legs. This process is called atherosclerosis.
People with PAD can experience painful aching in their leg muscles during physical activity, because the muscles are not receiving the blood supply they need.
Like all tissue in your body, muscles in your legs need a constant supply of blood to function properly. When you are using your leg muscles, the demand for blood increases significantly. But if the arteries in your legs are blocked, the supply of available blood cannot meet the demand.
This shortfall between supply and demand causes your muscles to experience painful aches, which usually get better when you rest your legs.
There are some risk factors for PAD that cannot be changed, such as a family history of heart disease and atherosclerosis, or your age.
As you get older, your arteries naturally begin to harden and get narrower, which can lead to atherosclerosis and then PAD.
However, there are many things that can dangerously speed up this process, which are described below.
Smoking is the single most important factor that increases your risk of PAD. Smoking can damage the walls of your arteries. Tiny blood cells, known as platelets, will then form at the site of the damage to try to repair it, which can cause your arteries to narrow.
It is estimated that more than 9 out of every 10 people who develop PAD smoke or have done so in the past.
If you have poorly controlled type 1 diabetes or type 2 diabetes, the excess glucose in your blood can damage your arteries and increase your risk of developing PAD. Around 2 out of every 10 people with PAD has diabetes.
People who have poorly controlled diabetes and PAD are also more likely to eventually need an amputation as a result of severely restricted blood flow to the legs.
Cholesterol is a type of fat that is essential for the body to function.
There are two main types of cholesterol:
Low-density lipoprotein (LDL) is the main cholesterol transporter, and carries cholesterol from your liver to cells that need it. If there is too much cholesterol for the cells to use, this can cause a harmful build-up in your blood and lead to atherosclerosis. For this reason, LDL cholesterol is sometimes called "bad cholesterol".
High-density lipoprotein (HDL) carries cholesterol away from the cells and back to the liver, where it is either broken down or passed from the body as a waste product. For this reason, it's sometimes called "good cholesterol".
Most of the cholesterol your body needs is made by your liver. However, if you eat foods high in saturated fat, the fat is broken down into LDL, which is then passed into your blood vessels.
High blood pressure
Your arteries are designed to pump blood at a certain pressure, and if blood pressure is too high (known as hypertension), the walls of the arteries can become damaged.
High blood pressure can be caused by:
drinking excessive amounts of alcohol
a lack of exercise
Diagnosing peripheral arterial disease
If your GP suspects peripheral arterial disease (PAD), they will carry out a physical examination of your legs.
PAD can cause various symptoms – some of which your GP will be able spot, but you may not – such as:
hair loss on your legs and feet
the pulse in your leg being very weak or undetectable
Your GP may also ask about your symptoms and your personal and family medical histories.
The ankle brachial pressure index
The ankle brachial pressure index (ABPI) test is widely used to diagnose PAD, as well as assessing how well you are responding to treatment.
While you rest on your back, your GP or practice nurse will measure the blood pressure in your upper arms and your ankles. These measurements are taken with a Doppler probe, which uses sound waves to determine the blood flow in your arteries.
They then divide the second result (from your ankle) by the first result (from your arm).
If your circulation is healthy, the blood pressure in both parts of your body should be exactly or almost the same, and the result of your ABPI would be one.
However, if you have PAD, the blood pressure in your ankle will be lower due to a reduction in blood supply, so the results of the ABPI would be less than one.
In some cases, ABPI may be carried out after getting you to run on a treadmill or cycle on an exercise bike. This is a good way to see the effect of physical activity on your circulation, although it will usually need to be done in hospital, as most GP surgeries do not have the facilities to perform this test.
In most cases, your GP will be able to confirm a diagnosis of PAD by doing a physical examination, asking about your symptoms and checking your ABPI score.
Further testing is usually only required if:
there is uncertainty about the diagnosis – for example, if you have leg pain but your ABPI score is normal
you do not fit the expected profile of somebody with PAD – for example, you are young and have never smoked
the restriction of blood supply in your leg is severe enough that treatment, such as surgery, may be required
Additional hospital-based tests that can be used include:
an ultrasound scan – where sound waves are used to build up a picture of arteries in your leg; this can identify exactly where in your arteries there are blockages or narrowed areas
an angiogram – wherea special liquid known as a contrast agent is injected into a vein in your arm; the agent shows up clearly on a computerised tomography (CT) scan or magnetic resonance imaging (MRI) scan and produces a detailed image of your arteries
In some cases, the contrast agent may be injected directly into the arteries of your leg, and X-rays may be used to produce the images.
Complications of peripheral arterial disease
The blockages in the arteries that cause peripheral arterial disease (PAD) can also lead to other serious problems, such as critical limb ischaemia (CLI).
Critical limb ischaemia
CLI occurs in cases of PAD where the blood flow to the legs becomes severely restricted. It's estimated that around one in every five people with symptoms of PAD will develop CLI at some point.
Symptoms of CLI include:
a severe burning pain in your legs and feet that continues even when you are resting
your skin turning pale, shiny, smooth and dry
wounds and ulcers (open sores) on your feet and legs that don't heal
loss of muscle mass in your legs
the skin on your toes or lower limbs becoming cold and numb, turning red and then black, and/or beginning to swell and produce foul-smelling pus, causing severe pain (gangrene)
If you think you are developing symptoms of CLI, contact your GP immediately. If this is not possible, telephone 111 or your local out-of-hours service.
CLI is an extremely serious complication that can be challenging to treat.
An angioplasty or bypass graft (read about treating PAD for more information on these operations) will usually be recommended if you have CLI, although these may not always be successful or possible. In a few cases, an amputation below the knee may be required.
Increased risk of cardiovascular disease
Cardiovascular disease (CVD) is a general term that describes a condition affecting the heart or blood vessels. Along with PAD, there are a number of different forms of CVD – including coronary heart disease, stroke, heart attack and angina.
While PAD itself does not directly cause other forms of CVD, the condition is a sign that the blood vessels in your legs are in bad health.
The blockages in the arteries in the legs that cause PAD can also affect other areas of your body, such as the arteries supplying the heart and brain, which means that having the condition makes you more likely to develop another form of CVD.
Preventing peripheral arterial disease
The most effective way to prevent peripheral arterial disease (PAD) or stop the condition getting worse is to tackle the build-up of fatty substances in your arteries (atherosclerosis).
There are five main ways you can achieve this:
eat a healthy diet
stop smoking, if you smoke
lose weight, if you are overweight or obese
moderate your consumption of alcohol
These lifestyle changes are discussed in more detail below.
Eating an unhealthy diet that is high in fat can cause fatty plaques to build up in your arteries. This is because fatty foods contain cholesterol.
There are also two types of fat – saturated and unsaturated. Avoid foods containing saturated fats, because they will increase the levels of "bad cholesterol" in your blood.
Foods high in saturated fat include:
sausages and fatty cuts of meat
ghee (a type of butter often used in Indian cooking)
cakes and biscuits
food that contains coconut or palm oil
However, it is not healthy to completely cut out all types of fat from your diet. It is important to replace saturated fats with unsaturated fats, as they can help increase levels of "good cholesterol" and reduce blockage in your arteries.
Foods that are high in unsaturated fat include:
oily fish (mackerel, salmon, tuna)
nuts and seeds
sunflower, rapeseed and olive oil
Read more detailed information on the facts about fat and how to eat less saturated fat.
Eating a low-fat diet including lots of fibre, such as wholegrain rice, bread and pasta, and plenty of fruit and vegetables, may also help to lower cholesterol. Fruit and vegetables are full of vitamins, minerals and fibre, and help keep your body in good condition. Aim to eat five 80g portions of fruit and vegetables every day.
If you smoke, it is strongly recommended that you quit as soon as possible.
If you decide to stop smoking, your GP can refer you to an Smokefree service, which will offer dedicated help and advice about the best ways to quit.
You can also call the Smokefree helpline on 0300 123 1044 (7am to 11pm). The specially trained helpline staff offer free expert advice and encouragement.
If you are committed to giving up smoking but do not want to be referred to a stop smoking service, your GP should be able to prescribe treatment to ease your withdrawal symptoms.
If you do not have PAD, a minimum of 150 minutes of vigorous exercise a week is recommended. The exercise should be strenuous enough to leave your heart beating faster, and you should feel slightly out of breath afterwards.
Activities you could incorporate into your exercise programme include:
If you find it difficult to achieve 150 minutes of exercise a week, start at a level you feel comfortable with. For example, you could do 5 to 10 minutes of light exercise a day and then gradually increase the duration and intensity of your activity as your fitness begins to improve.
For guidance on exercise for people with PAD,,
Maintain a healthy weight
If you are overweight or obese, aim to lose weight and maintain a healthy weight by using a combination of regular exercise and a calorie-controlled diet.
Cut down on alcohol
If you drink alcohol, do not exceed recommended daily limits (three to four units a day for men and two to three units a day for women).
A unit of alcohol is roughly half a pint of normal-strength lager or a single measure (25ml) of spirits.
Regularly exceeding recommended alcohol limits can raise your blood pressure and cholesterol level, which can cause your blood vessels to become damaged or narrowed.
Contact your GP if you find it difficult to moderate your drinking. Counselling services and medication can help you reduce your alcohol intake.
Peripheral arterial disease (PAD)