What Is Plethysmography – Indications, Procedures, Results

Last updated: February 8, 2026 Medically reviewed by: RxHarun Orthopedic Specialist Doctor Reading time: 2 min read

Plethysmography – limb

Limb plethysmography is a test that compares blood pressure in the legs and arms.

How the Test is Performed

This test may be done in the health care provider’s office or in a hospital. You will be asked to lie with the upper part of your body slightly raised.

Three or four blood pressure cuffs are wrapped snugly around your arm and leg. The provider inflates the cuffs, and a machine called a plethysmograph measures the pulses from each cuff. The test records the maximum pressure produced when the heart contracts (systolic blood pressure).

Differences between the pulses are noted. If there is a decrease in the pulse between the arm and leg, it may indicate a blockage.

When the test is complete, the blood pressure cuffs are removed.

How to Prepare for the Test

Do not smoke for at least 30 minutes before the test. You will be asked to remove all clothing from the arm and leg being tested.

How the Test will Feel

You should not have much discomfort with this test. You should only feel the pressure of the blood pressure cuff. The test often takes less than 20 to 30 minutes to perform.

Why the Test is Performed

This test is most often done to check for narrowing or blockages of blood vessels (arteries) in the arms or legs.

Normal Results

There should be less than a 20 to 30 mm Hg difference in the systolic blood pressure of the leg compared with that of the arm.

What Abnormal Results Mean

Abnormal results may be due to:

Arterial occlusive disease
Blood clots
Blood vessel changes due to diabetes
Injury to an artery
Other blood vessel disease (vascular disease)

Other conditions for which the test may be performed:

Deep venous thrombosis

If you have an abnormal result, you may need to have more testing to find the exact site of the narrowing.

Risks

There are no risks.

Considerations

This test is not as accurate as an arteriography . Plethysmography may be done for very ill people who cannot travel to the arteriography lab. This test can be used to screen for vascular disease or to follow up earlier abnormal tests.

The test is noninvasive, and it does not use x-rays or injection of dye. It is also less expensive than an angiogram.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area later with a custom field named _rx_references.

Written by Dr. Harun Ar Rashid, MD - Arthritis, Bones, Joints Pain, Trauma, and Internal Medicine Specialist

Dr. Md. Harun Ar Rashid, MPH, MD, PhD, is a highly respected medical specialist celebrated for his exceptional clinical expertise and unwavering commitment to patient care. With advanced qualifications including MPH, MD, and PhD, he integrates cutting-edge research with a compassionate approach to medicine, ensuring that every patient receives personalized and effective treatment. His extensive training and hands-on experience enable him to diagnose complex conditions accurately and develop innovative treatment strategies tailored to individual needs. In addition to his clinical practice, Dr. Harun Ar Rashid is dedicated to medical education and research, writing and inventory creative thinking, innovative idea, critical care managementing make in his community to outreach, often participating in initiatives that promote health awareness and advance medical knowledge. His career is a testament to the high standards represented by his credentials, and he continues to contribute significantly to his field, driving improvements in both patient outcomes and healthcare practices. Born and educated in Bangladesh, Dr. Rashid earned his BPT from the University of Dhaka before pursuing postgraduate training internationally. He completed his MD in Internal Medicine at King’s College London, where he developed a special interest in inflammatory arthritis and metabolic bone disease. He then undertook a PhD in Orthopedic Science at the University of Oxford, conducting pioneering research on cytokine signaling pathways in rheumatoid arthritis. Following his doctoral studies, Dr. Rashid returned to clinical work with a fellowship in interventional pain management at the Rx University School of Medicine, refining his skills in image-guided joint injections and minimally invasive pain-relief techniques.