What is a Doppler ultrasound?

Healthcare professionals use ultrasounds to examine internal structures, such as bones and organs. They use a Doppler ultrasound to analyze how well blood is flowing through the veins and arteries.

A Doppler ultrasound uses sound waves to create images of how a person’s blood is flowing through their veins and arteries. The goal is often to check blood flow through the arms and legs.
During a Doppler ultrasound, a handheld device emits sound waves that bounce off moving objects, such as blood cells. The reflected sound waves create an image of the way the blood is flowing.

There are several types of Doppler ultrasound:
-A color Doppler helps visualize the movement, speed, and direction of blood flow in color.
-A power Doppler is a newer form of color Doppler that provides more detail, but it cannot show in which direction blood is flowing.
-A duplex Doppler takes a standard image of a blood vessel and graphs the data.
-A spectral Doppler shows blood flow as graphed data, and it can show whether the blood flow is blocked.
-A continuous-wave Doppler sends a continuous stream of soundwaves, which allows the ultrasound to more accurately measure blood moving at faster speeds.

What is it used for?
Healthcare professionals use Doppler ultrasound to learn about a person’s blood flow, particularly whether there are any blockages or other irregularities.
The results can help doctors diagnose various conditions, including certain heart conditions.
For example, doctors use Doppler ultrasound to check for:
-blood vessel damage
-irregularities in the structure of the heart
-blockages, such as deep vein thrombosis
-narrowing or hardening of blood vessels, which can interrupt blood flow to the feet and legs
-superficial thrombophlebitis, which involves inflammation in a leg vein
-vascular tumors in the legs
-thromboangiitis obliterans, a rare disease that causes blood vessels in the hands and feet to swell
-any changes in heart function, often alongside an electrocardiogram
-any changes in blood flow following surgery
-any changes in blood flow during pregnancy or in the fetus

Why does a person need one?
A doctor may order a Doppler ultrasound if a person shows signs of reduced blood flow to the arms, neck, or legs.
The following, for example, can reduce blood flow:
-blood clots in veins
-blockages or narrowing of arteries
-injuries to blood vessels
Typically, a healthcare provider recommends a Doppler ultrasound if a person shows signs or symptoms of certain conditions, such as peripheral arterial disease. This occurs when fatty deposits collect in arteries, restricting blood flow.
Peripheral arterial disease can cause:
-coldness in the feet or lower parts of the legs
-weakness or numbness in the legs
-painful cramping in the leg muscles or hips while walking or climbing stairs
-changes in the color of the skin
-shiny skin on the legs
In other cases, a doctor may order a Doppler ultrasound if a person has symptoms of a heart condition, such as:
-fatigue
-shortness of breath
-swelling in the feet, legs, or abdomen
Generally, a doctor tends to order this type of ultrasound when a person:
-may have damaged blood vessels
-is currently receiving treatment for a blood flow disorder
-has recently had a stroke, in which case they will check blood flow in the brain, and the procedure is called a transcranial Doppler.

Also, if a fetus is smaller than expected, a Doppler ultrasound can look for any irregularities in blood flow.