A kidney ultrasound is a quick and painless medical procedure that can provide information regarding the health of your kidneys.

Doctors can use ultrasound imaging to assess the general health of your kidneys and look for signs of injury, cancer, and kidney failure.

In this article, we detail what a kidney ultrasound is and what it can detect, what you need to do to prepare for one, and how much it can cost.

A kidney ultrasound is a noninvasive exam that uses sound waves to produce images of your kidneys. People may also call this a renal ultrasound. The word “renal” refers to anything related to your kidneys.

Ultrasound, or sonography, uses high frequency sound waves sent out by a transducer (wand) pressed against your skin. The sound waves move through your body, bouncing off organs back to the transducer.

These echoes are recorded and digitally turned into video or images of the tissues and organs selected for examination.

Ultrasound images can help your doctor evaluate:

  • the location of your kidneys
  • the size of your kidneys
  • the shape of your kidneys
  • blood flow to your kidneys

It can also help them detect signs of:

A kidney ultrasound usually includes your bladder, too.

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If your doctor orders a kidney ultrasound, they’ll give you specific instructions about how to prepare and what to expect. Be sure ask to ask questions if any of the information they provide is unclear.

It’s possible that you may be asked to drink several glasses of water in the hours before your exam. This can help to ensure that good-quality images are collected during the ultrasound.

You will typically not have to fast before a kidney ultrasound. However, if you are having an ultrasound to assess the arteries in your kidneys, you must fast beforehand.

Plan to continue to take all of your medications as usual unless your doctor tells you otherwise.

A kidney ultrasound is a short, noninvasive procedure. It typically takes about 20 to 30 minutes to complete and involves the following steps:

  1. When you arrive for your ultrasound, you’ll be asked to remove your clothing and jewelry and change into a medical gown.
  2. You’ll then be taken to the room where you will get the ultrasound. This room is typically kept dark.
  3. You’ll be instructed to lie down on an exam table that’s located next to the ultrasound equipment.
  4. The technician doing the ultrasound will spread a gel onto your skin in the area of the kidneys. This gel helps to better conduct the sound waves produced by the transducer.
  5. The technician will then rub the transducer against your abdomen. At certain points during the ultrasound, they may ask you to hold your breath or roll onto your side.
  6. The sound waves generated by the transducer will bounce back from your organs. A computer will capture these echoes and create images of your kidneys and bladder.

You’ll be able to eat and drink as usual after your ultrasound. Additionally, you can return to your daily activities after you leave the facility.

After the ultrasound, the technician will forward the results to a radiologist. This is a type of doctor that specializes in making sense of medical images, such as those created by ultrasound.

Once the radiologist has reviewed your images, which typically takes only 1 or 2 days, they’ll send their findings to your doctor. Your doctor will then contact you to go over the results of your ultrasound.

Ultrasound isn’t hazardous and there are no known harmful side effects. Unlike X-ray tests, ultrasounds do not use radiation.

Overall, the procedure is noninvasive and painless. You might feel uncomfortable lying on the table, and the gel and transducer might feel cold. Additionally, if you’ve been asked to drink water prior to your ultrasound, you may have some discomfort from having a full bladder.

It’s also possible that waiting for your results may cause you some anxiety. To help alleviate this, ask your doctor how long it should take to receive your results. Don’t hesitate to contact them if this window passes and you haven’t heard anything.

Online estimates place the average price of abdominal ultrasound scans at $410.

Through Medicare, the average payment for ultrasound in hospital outpatient departments is $28.

However, keep in mind that this is an average and that costs may be higher or lower depending on factors like:

  • whether you have health insurance
  • your location
  • the facility where you have your procedure

Generally speaking, most insurance plans will cover a kidney ultrasound if it’s considered medically necessary to diagnose or treat a health condition. You may be responsible for paying coinsurance or copay. Be sure to ask your insurance provider what’s covered prior to your ultrasound.

Your doctor may recommend a kidney ultrasound if they think you have a kidney problem and they need more information. Your doctor might be concerned about:

A kidney ultrasound may also be used to help detect physical signs of chronic kidney disease (CKD), which can lead to kidney failure. For example, the kidneys of someone with CKD may be smaller, have thinning of certain kidney tissues, or show the presence of cysts.

Other reasons you might need a kidney ultrasound include:

A kidney ultrasound is a noninvasive, painless medical procedure that only takes about 30 minutes to complete. It can help to give your doctor the needed details to properly diagnose a suspected kidney concern.

Depending on the results of your kidney ultrasound, your doctor may order additional tests. Some examples include laboratory tests on blood or urine samples, additional imaging tests, or a kidney biopsy.

With the information provided by your ultrasound and other tests, your doctor can customize a plan to help treat your condition and your symptoms. If ever you have any questions about a particular procedure, test, or treatment, don’t hesitate to ask your doctor.