A kidney ultrasound is a common imaging test used to visualize the kidneys and surrounding structures. While generally safe and non-invasive, experiencing discomfort or pain during or after the procedure can be concerning. Mild sensations are typical, but significant pain is not and may indicate an underlying issue.
What is a Kidney Ultrasound
A kidney ultrasound, also known as a renal ultrasound, uses high-frequency sound waves to create real-time pictures of the kidneys and bladder. This non-invasive procedure helps healthcare providers assess kidney size, shape, and location, and detect abnormalities like kidney stones, infections, cysts, or blockages.
A handheld transducer generates sound waves that bounce off organs, creating echoes. A computer converts these echoes into images displayed on a screen. This method is safe as it does not use radiation, unlike X-rays or CT scans.
Expected Sensations During a Kidney Ultrasound
During a kidney ultrasound, patients typically lie on an examination table. A water-soluble gel is applied to the skin over the abdomen or back. This gel helps the transducer move smoothly and ensures optimal contact for sound wave transmission. The gel may feel cool.
As the sonographer moves the transducer across the skin, a mild pressure is usually felt. This pressure is necessary to obtain clear images of the kidneys. Patients may also be asked to hold their breath at various points to improve image quality. These sensations are generally not painful and are considered normal aspects of the procedure.
Reasons for Pain or Significant Discomfort
While a kidney ultrasound is often painless, experiencing significant discomfort or pain can occur due to several factors, often related to pre-existing conditions or aspects of the procedure itself. The pressure from the transducer can sometimes exacerbate pain from underlying issues.
Pre-existing kidney conditions are a common cause of pain during an ultrasound. Conditions like kidney stones can cause sharp, cramping pain, and the pressure applied during the scan might aggravate this discomfort, especially if stones are moving. Kidney stones are solid pieces of salts and minerals that form in the kidneys and can cause pain if they block urine flow.
Kidney infections, known as pyelonephritis, can make the kidneys inflamed and tender. The gentle pressure of the ultrasound transducer over an infected kidney can lead to increased pain. Symptoms of a kidney infection often include fever, chills, and pain in the lower back or side.
Hydronephrosis, which is the swelling of one or both kidneys due to urine backup, can also cause pain during an ultrasound. The kidney becomes distended from accumulated urine, making it more sensitive to external pressure. This condition can result from blockages in the urinary tract.
Kidney cysts, which are fluid-filled sacs on the kidneys, typically do not cause symptoms unless they are very large, infected, or rupture. If a cyst is already causing pain or is inflamed, the pressure from the ultrasound can intensify this sensation.
General inflammation of the kidney tissue (nephritis) can also make the organ sensitive. Any underlying inflammation will cause the kidney to be more tender than usual, and the physical contact of the transducer can lead to discomfort.
Beyond underlying conditions, procedural factors can contribute to discomfort. Sonographers sometimes need to apply firm pressure with the transducer to get clear images, especially in individuals with more tissue over the kidney area. This necessary pressure can be uncomfortable for some patients.
Discomfort can also arise from a very full bladder, which is often required for the scan to obtain optimal images of the bladder and surrounding structures. The sensation of needing to urinate intensely, combined with external pressure, can be unpleasant. Patients are typically asked to drink a certain amount of water beforehand and not empty their bladder until after the scan.
In some cases, discomfort may not be directly related to the kidneys but rather be referred pain or general body soreness. Gas or bowel discomfort in the abdominal area can be felt during the scan, or muscle soreness might develop from lying in an awkward position for the duration of the procedure.
When to Seek Medical Attention
If you experience pain or significant discomfort during or after a kidney ultrasound, certain signs indicate that you should seek prompt medical attention.
Contact your healthcare provider if you experience persistent or worsening pain in your side, back, or abdomen after the ultrasound. Other concerning symptoms include fever, chills, or any signs of infection.
The presence of blood in your urine, severe nausea, vomiting, or an inability to urinate also warrants immediate medical evaluation. Pain that radiates to other areas, such as the groin, should also be reported.