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

This test is usually done to check for blood flow blockages in the legs. It is done to help rule out blocked arteries in the arms or legs.

This test may be done in the health care provider's office or in a hospital. You will be asked to lie in a partially propped-up position.

Three blood pressure cuffs are wrapped snugly around your arm and leg. The health care 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).

Any 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.

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.

You should not have much discomfort with this test. You should only feel the pressure of the blood pressure cuff.