Peripheral arterial disease (PAD) happens when there is a narrowing or blockage of the blood vessels that take blood to the legs. 

What is peripheral arterial disease (PAD)?

The tubes that carry blood to the legs are called arteries. The blood in the arteries contains the oxygen that leg muscles need to work properly.

Peripheral arterial disease (PAD) happens when the sides of the arteries are narrowed by a build-up of fatty material. The narrow arteries cannot take as much blood the leg muscles which means that the muscles do not get as much oxygen. This is usually only a problem when walking because that is when the leg muscles need more oxygen.

If the narrowing is very severe or an artery becomes blocked by a blood clot, then the symptoms of PAD can happen even at rest.

Peripheral arterial disease (PAD) is sometimes known as peripheral vascular disease (PVD).

What symptoms does peripheral arterial disease (PAD) cause?

Intermittent claudication: The most common symptom is a cramping and aching pain in the calves when walking - this is called intermittent claudication. Some people feel the pain in their feet, thighs or buttocks. The pain gets better after resting for a few minutes. The pain comes on more quickly if walking fast or uphill. PAD often affects both legs, although one may be worse than the other. Usually, intermittent claudication comes on gradually over time.

Sometimes, the pain will become less of a problem after a few weeks. This is because there are smaller arteries around the main arteries to the leg. These can enlarge to try to increase the amount of blood getting to the leg muscles.

If the narrowing becomes very severe, the pain may come on when resting or wake you up at night. This is called “critical limb ischaemia”.

Other symptoms:

• numbness or a feeling of pins and needles in the legs
• one foot may feel colder than the other
• toenails that are brittle and grow slowly
• ulcers (open sores) on your feet and legs – these can be difficult to treat. They may be slow to heal or may not heal at all.
• loss of hair on your legs and feet
• change in the colour of the skin on your legs – the skin can look paler than usual or blue
• shiny skin
• weakness in the legs
• shrinking of the leg muscles

Acute limb ischaemia: This is a rare medical emergency. It is due to a blood clot forming over a damaged area of fatty build up and blocking the artery. The skin on the toes or lower limbs suddenly becomes cold and numb, turning red and then black (gangrene). The skin can also swell, become infected and produce smelly pus, causing severe pain. If you notice these symptoms, you must call a doctor immediately.

How is peripheral arterial disease (PAD) diagnosed?

If you are having symptoms that may be due to PAD, you should see your doctor who will talk to you about those symptoms and examine you.

Your doctor will check your pulses and compare the blood pressure in your arm with the blood pressure at your ankle. This measurement is called your ankle brachial pressure index (ABPI).

If your ABPI suggests you have PAD, your doctor will refer you to a specialist called a Vascular surgeon. You may also need blood tests to look for a cause of the PAD. The vascular surgeon may order more specialised tests such as:

	Duplex ultrasound: A soundwave scan to look at the flow of the blood in the arteries. A duplex ultrasound is similar to the ultrasound scan that pregnant women have.
	Arteriogram: An arteriogram is way of looking at the arteries and showing any areas of narrowing or blockage. To do an arteriogram, an X-ray specialist (radiologist) will inject a small amount of dye into a blood vessel and then take pictures of the arteries using X-rays, computed tomography (CT) or magnetic resonance imaging (MRI).