A to Z Health Guide

What Is Kidney Atrophy?

Normally, kidneys are about the size of a fist or 10 to 12 cm (about 5 inches). Kidney atrophy means that the kidney is smaller than normal. This can happen for two basic reasons. The first is that part of the kidney does not develop from birth (called a congenital problem) making a small kidney. This type of kidney atrophy or small kidney usually does not need any special treatment. The second type happens after birth, which can occur in one or both kidneys. This type of kidney atrophy is due to a lower blood supply to the kidney(s)and/or loss of nephrons, the basic working units of the kidneys. Chronic infections or blockage of the kidney can also result in kidney atrophy. A kidney that is smaller in size can lead to kidney disease. A greater decrease in kidney size, especially for both kidneys, can lead to kidney failure.

What causes kidney atrophy?

Kidney atrophy may be due to:
  • Blocked kidney artery (known as renal artery stenosis) – blocks the main arteries that supply blood to the kidneys, which can be due to hardening of the arteries with fatty deposits or blood clots
  • Blocked urinary tract – blocks the normal flow of urine which leads to pressure on the kidneys and damages the nephrons
  • Kidney stones – an untreated kidney stone can cause a kidney blockage
  • Long-lasting kidney infections such as pyelonephritis, polycystic kidney disease, and other chronic kidney diseases that can damage nephrons

What are the symptoms of kidney atrophy?

Some symptoms of kidney atrophy include pain while passing urine, pain in the abdomen (belly) or flank (side and back), blood in urine, urinating more often, feeling tired (fatigue), loss of appetite, itchy skin, general discomfort in the kidney area, muscle cramps and swelling of the hands and feet. Sometimes kidney atrophy can have no symptoms, especially if the cause is slow and over many years.

How is kidney atrophy diagnosed?

Tests for kidney atrophy include imaging tests such as ultrasound, computed tomography (CT or CAT) scan, or magnetic resonance imaging (MRI). Early diagnosis and treatment of kidney atrophy is important to avoid further kidney damage.

How is kidney atrophy treated?

The treatment for kidney atrophy depends on what caused the kidney to become smaller in the first place. For example, a patient with kidney atrophy due to chronic urinary tract infection would need antibiotics.
 
Kidney atrophy can be singular (one kidney) or bilateral (both kidneys). Your doctor will find out how much kidney function is left through blood and urine tests. If the kidney is not working at all, kidney removal is not usually required unless there is an ongoing problem such as repeated infection. If the kidney is still filtering or working, there may be medical treatment to keep the kidney function that’s left. If both kidneys fail, then the treatment is dialysis or kidney transplant.
 
Think about kidney health by controlling your blood pressure, not smoking, treating your diabetes if you have it, keeping a healthy weight, and eating a low salt healthy diet. It is also important to follow-up with your doctor for regular check-ups

The information shared on our websites is information developed solely from internal experts on the subject matter, including medical advisory boards, who have developed guidelines for our patient content. This material does not constitute medical advice. It is intended for informational purposes only. No one associated with the National Kidney Foundation will answer medical questions via e-mail. Please consult a physician for specific treatment recommendations.