Definition and Overview

A carotid Doppler test is a diagnostic procedure that employs ultrasound to observe the flow of blood in the carotid arteries, located in the neck and the blood flow in the subclavian and vertebral arteries. The procedure is typically performed to assess the extent of atherosclerotic disease, a condition characterized by the build-up of plaque inside the arteries.

Atherosclerotic disease can be life-threatening if left undiagnosed or untreated as it reduces the amount of oxygen-rich blood flowing into the brain. In addition, the blocked arteries can harden and break open resulting in blood clot that can prevent blood from flowing in the carotid arteries.

Who Should Undergo and Expected Results

A carotid Doppler procedure is usually recommended for patients with an increased risk of stroke as well as those who suffer or are experiencing the following conditions:

  • Diabetes
  • High cholesterol levels
  • High blood pressure
  • A stroke or a transient ischemic attack in the last couple of months

Patients with a family history of heart disease and stroke should also undergo this procedure at least once a year as a preventative measure. The procedure can also be prescribed if the diagnosing physician detects abnormal sound using a stethoscope. In the event that the patient has serious plaque build-up in the carotid arteries, the doctor can prescribe medication and surgery as treatment.

How is the Procedure Performed?

Like with an ultrasound procedure, a sonographer (the technician performing the carotid Doppler) uses a transducer, a hand-held device that emits sound waves. Echoes will be created by these sound waves as they bounce off the internal structures. These echoes will then be transmitted to a computer, which will produce a graph containing information on how the blood flows through the carotid arteries.

During the procedure, the patient will lie on his or her back. A warm gel will be applied to the skin of the neck, near the carotid arteries. The sonographer will then press the transducer against the sides of the neck.

The whole procedure takes around half an hour, and should not cause any pain or discomfort to the patient. The resulting graph from the procedure will be sent to a cardiologist or the patients’ diagnosing physician.

Possible Risks and Complications

Carotid Doppler is a very safe procedure, and can be performed without serious risk or side effects to the patient.


  • Fowler GC, Reddy B. Noninvasive Venous and Arterial Studies of the Lower Extremities. In: Pfenninger JL, Fowler GC, eds. Pfenninger & Fowler's Procedures for Primary Care. 3rd ed. Philadelphia, PA: Elsevier Mosby; 2011:chap 88.
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