Renal Atrophy - Causes, Signs and Symptoms, Diagnosis, and Management

Introduction:

The normal human kidneys are a pair of bean-shaped organs on either side of the backbone, below the ribs. Each kidney is about the size of a fist and around four to five inches long. The left kidney is a little bigger than the right kidney. The left kidney is placed slightly higher and closer to the heart than the right kidney. An atrophic kidney is a kidney that has reduced to an abnormal size. It should not be confused with a condition known as renal hypoplasia, wherein an individual is born with a smaller kidney. Atrophy can affect one or both kidneys, but the left one is more likely to be affected. An atrophic kidney may lead to kidney disease and can eventually lead to kidney failure.

What Causes Kidney Atrophy?

Kidney atrophy might be caused due to following:-

• Renal Artery Stenosis - It is a condition where there is blockage of the blood vessels supplying blood to the kidneys. This is caused due to the hardening of the blood vessels caused by the deposition of fat or blood clots.

• Blocked Urinary Tract - Blockage in the urinary tract restricts the normal flow of urine and puts pressure on the kidneys damaging the kidney cells.

• Kidney Stones - Kidney stones, if left untreated, can lead to kidney blockage and a reduction in kidney size.

• Kidney Infections - Untreated kidney infections such as pyelonephritis, polycystic kidney disease, and other chronic kidney diseases can harm the kidney cells causing shrinkage in the kidney size.

• Antiphospholipid Syndrome - A disorder of the immune system.

• Tuberculosis - Infectious disease of the lungs.

• Metabolic Syndrome - A group of conditions that increases the risk of heart disease, stroke, and diabetes.

• Atherosclerosis - The hardening of the blood vessels.

• Sickle Cell Disease - A disorder that causes the red blood cells to go out of shape and break down.

• Cancer.

Who Is at Risk of Developing Renal Atrophy?

People having certain disease conditions are at a higher risk of developing kidney atrophy:-

• Diabetes.

• Family history of kidney disease.

• Heart disease.

• Hypertension or high blood pressure.

What Are the Signs and Symptoms of Renal Atrophy?

Kidney disease at the beginning is usually asymptomatic. Then, a loss of around thirty to forty percent of kidney function causes symptoms.

• Increased frequency of urination.

• Skin darkening.

• Sleepiness.

• Itching of the skin.

• Loss of appetite.

• Muscle Cramps.

• Nausea and vomiting.

• Pain while passing urine.

• Pain in the belly or the side and back of the body.

• Hematuria - Blood in the urine.

• Fatigue.

• Swelling of the hands and feet.

• Acidosis.

• Anorexia.

• High concentration of creatinine.

• Abnormalities related to electrolyte imbalance.

• Malnutrition.

How Is Kidney Atrophy Diagnosed?

Various tests are done to diagnose kidney atrophy. Tests such as GFR (glomerular filtration rate) are done to check the function of the kidney.

1. GFR (Glomerular Filtration Test) - This is a blood test to measure how well the kidneys function. The Normal range of GFR is sixty or more. A GFR of less than sixty might suggest the presence of kidney disease. A GFR as low as fifteen or lesser indicates kidney failure. GFR is estimated by measuring the creatinine levels in the blood. Creatinine is the waste product of the normal wear and tear of the muscle. Creatinine levels increase as the kidney disease progresses. Therefore, a GFR of less than sixty would require additional tests to be conducted. However, in the case of a GFR of fifteen or lower, regular dialysis or kidney transplant may be required.

2. Albumin Test - An urine test is done to detect the presence of urine in the body. Albumin is a protein present in the blood. A healthy kidney would not allow the passage of albumin in the urine. The presence of albumin in the urine means the kidneys are not working properly. The dipstick or urine albumin-to-creatinine ratio test can detect albumin in the urine.

• Dipstick Test - It is a chemically treated paper called a dipstick. This dipstick is placed in the urine sample. A color change suggests the presence of albumin.

• Urine Albumin-to-Creatinine Ratio - This test compares the albumin and creatinine in the urine.

3. Ultrasound - This diagnostic procedure uses sound waves to develop an image of the internal organs. A renal ultrasound gives a detail about the urinary system. It helps to detect the presence of atrophic kidneys.

4. CT Scan - A computerized tomography urogram is a scan that provides images of the urinary tract consisting of the kidneys, urinary bladder, and ureters. It uses X-rays to create images of the organs. It can also diagnose conditions that can cause renal atrophy, such as cancer, bladder stones, tumors or cysts, some structural issues, and kidney stones.

Doctors can also use these tests to assess whether the treatment is working. However, these tests alone are not conclusive of kidney atrophy.

How Is Kidney Atrophy Treated?

Most of the treatment modality depends on the cause of the atrophy. Treating the underlying condition causing renal atrophy may prevent further kidney damage. For example, atrophic kidneys might still be working well. But if the kidneys function at less than ten to 15 percent, it suggests kidney failure and needs treatment.

• Dialysis - Blood is run through the artificial kidney equipment known as the hemodialyzer that removes waste products during the procedure. Then, a fluid called dialysate is filled in the abdomen to filter out waste. Dialysis functions like the kidneys and should be done several times a week for the rest of the life unless and until a kidney transplant is done.

• Kidney Transplant - It is a surgical procedure in which a healthy kidney from a living or deceased donor is transplanted into a person's body. This is one of the last treatment modalities in case of kidney failure. After that, the individual has to take immunosuppression medication for the rest of their life.

How to Manage Kidney Atrophy?

• Atrophic kidneys might not function properly. Proper dietary intake can ease the burden on the kidneys.

• Protein intake should be limited. The more proteins one intake, the harder the kidneys work to eliminate the waste.

• Sodium consumption should be reduced. Foods that are rich in sodium cause the body to retain fluid. Too much fluid leads to high blood pressure causing strain on the kidneys.

• Foods with low phosphorus should be consumed. Atrophic kidneys can result in the build-up of phosphorus in the blood. Therefore, food such as fresh fruits and vegetables, rice, etc., should be included in the diet.

• Potassium intake should be reduced. Foods with low potassium content, such as carrots, apples, beans, etc., should be a part of the diet.

Conclusion:-

Renal atrophy refers to a condition in which both or one of the otherwise healthy kidneys shrinks in size due to certain disease conditions. The kidneys ultimately lose their function if the condition is not promptly treated. It results from conditions that restrict the blood supply to the kidneys, causing them to shrink in size. Renal atrophy is not reversible and can be managed through proper eating and maintaining a healthy lifestyle.