Diagnostic Ultrasound vs. Ultrasound Therapy for Chronic Pain

What’s the Difference?

ultrasound exam
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You may hear the term "ultrasound" thrown around here and there during your chronic pain diagnosis or treatments. With all of the types of ultrasound out there, it's easy to get confused. Here's what you should know about diagnostic ultrasounds and ultrasound therapy, which are commonly used in the diagnosis and treatment of chronic pain.

Diagnostic Ultrasounds

To get a clearer picture of what is going on under the skin, a doctor may order a diagnostic ultrasound.

Diagnostic ultrasounds use high-frequency sound waves that bounce around, providing a picture of specific areas in the body. If you think of the type of ultrasound used in pregnancy, you are picturing something pretty close to a diagnostic ultrasound for chronic pain.

Diagnostic ultrasounds may be used to determine the cause of pelvic pain, to diagnose tumors causing pain or to examine other structural abnormalities that may cause certain types of chronic pain.

Ultrasound Therapy

Ultrasound therapy is often performed by a physical therapist as a pain treatment. Ultrasound therapy can be used in two ways: thermally, as a heat agent, and mechanically, as a vibration agent. A physical therapist may choose one or both ultrasound approaches, depending on your chronic pain condition.

Thermal Ultrasound

This type of ultrasound therapy is like applying a very deep heat: It penetrates the deep tissues, warming them up to encourage the healing of soft tissues.

A physical therapist might use thermal ultrasound to treat a strained muscle that has not healed as expected.

Mechanical Ultrasound

This type of ultrasound causes tiny vibrations in the soft tissue, which can decrease swelling and inflammation in order to reduce some types of pain. Mechanical ultrasound, like thermal ultrasound, also promotes soft tissue healing.

A physical therapist might use mechanical ultrasound to break up deep scar tissues in the muscles or ligaments.

Which Is Right for You?

The type of ultrasound you will have depends on whether your doctor is focusing on your diagnosis or your treatment. If he or she is looking for a cause of your pain, you will probably receive a diagnostic ultrasound. This may take place in the office, at a clinic or in a hospital, depending on what kind of detail is needed.

If you have already been diagnosed and your doctor has ordered ultrasound treatment, you will be receiving ultrasound therapy, most likely performed by a physical therapist. This usually takes place in an outpatient therapy clinic, though it can be performed in the hospital setting if you are recovering there. Even if your doctor has ordered ultrasound therapy, you should expect to receive additional physical therapy as well, as ultrasound is often administered along with other treatments such as exercise and stretching.


Belanger, Alain-Yvan. Evidence-Based Guide to Therapeutic Physical Agents. Lippincott Williams & Williams. 2003.

Medline Plus Medical Encyclopedia. Abdominal Ultrasound. Accessed 8/2/09.

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