Diagnosis of PAD
Prompt diagnosis and treatment of peripheral artery disease can help prevent complications. If you are over 50 or have signs of PAD, see your doctor. PAD is diagnosed by listening to the blood in your arteries with a stethoscope, or through checking the blood pressure in your legs with cuffs, similar to the ones commonly used on your arm in a doctor's office. Diagnosis of peripheral artery disease also may involve taking a family and personal medical history and performing a physical examination and diagnostic tests (e.g., imaging tests, blood tests).
Patients with a family or personal history of high blood pressure, high cholesterol, or heart disease, who experience leg pain, especially during activity, should be evaluated for PAD.
A medical history includes important information about hereditary (genetic) conditions, such as diabetes and heart disease, the patient's smoking history and diet, and the onset and nature of symptoms (e.g., whether pain worsens during activity).
During physical examination, physicians often use a stethoscope to detect a weak or absent pulse and listen for an abnormal sound called a bruit, which may indicate a narrowing or blockage in an artery. The skin, hair, and nails are evaluated for signs of PAD (e.g., pale color, hair loss, poor nail growth) and any sores or wounds are examined carefully.
An ankle-brachial index (ABI) test also is performed during physical examination. In this test, blood pressure readings in the arms (conventional blood pressure measurements) are compared to blood pressure readings in the ankles. Ankle blood pressure normally is at least 90% of blood pressure in the arms. In patients who have PAD, ankle blood pressure may be less than 50% of conventional blood pressure measurements.
ABI takes about 10 minutes to perform. This test may be performed regularly (e.g., yearly) in patients who have PAD to monitor progression of the condition.
Although the ABI can help diagnose PAD, this test cannot identify which arteries are affected. In many cases, imaging tests are performed to confirm the diagnosis. These tests can detect reduced blood flow, locate narrowed arteries and blockages, and determine the severity of the condition.
Imaging tests that may be used to diagnose PAD include the following:
- Angiography—In this procedure, a contrast agent (dye) is injected into the bloodstream and a series of x-rays is taken as the dye moves through the arteries. This procedure produces an image called an arteriogram.
- Computed tomographic (CT) angiography—This procedure involves taking a series of x-rays to create cross-sectional images of the arteries, usually of the abdomen, pelvis, or legs.
- Magnetic resonance angiography (MRA scan)—In this test, radio waves and a magnetic field are used to produce detailed images of the arteries.
- Ultrasound, also called Doppler ultrasound, or duplex imaging—In this test, sound waves are used to produce images of the arteries.
- X-rays—Standard x-rays may be used to detect calcium deposits in the arteries; however, x-rays are rarely performed to detect PAD today.
Blood tests may be performed to screen for medical conditions, such as diabetes and high cholesterol.