The causes of kidney disease in children are different than in adults. The most common causes of kidney disease in children are:
- Kidney birth defects
- Genetic diseases
- Kidney infection
- Nephrotic syndrome
- Systemic diseases
- Kidney trauma or injury
- Problems with the urinary system
What are kidney birth defects?
In kidney disease, birth defects are physical problems with your child's kidneys that they have since birth. The problems happen to your baby during pregnancy.
Common kidney birth defects include having:
- Only one kidney instead of two (renal agenesis or solitary kidney)
- Two kidneys, but one of them does not work well/at all (renal hypodysplasia)
- A kidney that is in the wrong place, such as below, above or on the opposite side of the body compared to the usual place (ectopic kidney)
- Bladder or ureter abnormalities (urine flow is blocked and/or urine flow goes in reverse and "refluxes" from the bladder to the kidneys)
Doctors may not know why your child has a kidney birth defect. It may have been caused by a genetic disease or something that your baby was or was not exposed to during pregnancy, such as medicines the mother took while pregnant.
Most children with a kidney birth defect will not have major health problems and can live full, healthy lives. However, children with a kidney birth defect may have a higher chance of kidney disease later in life. If your child has a kidney birth defect, talk to their doctor about how often they should be checked for signs of kidney disease.
What are genetic diseases that cause kidney disease?
A genetic disease is passed down from one or both parents to your child through genes. Genes contain DNA and tell your cells what to do. You may also hear it called a hereditary or inherited disease. There is no way to prevent a genetic disease. There are medicines that can help treat and manage certain genetic diseases.
The most common genetic diseases that cause kidney disease are:
- Alport syndrome
- Polycystic kidney disease, either autosomal recessive polycystic kidney disease (ARPKD) or autosomal dominant polycystic kidney disease (ADPKD)
- Nephropathic cystinosis
Alport syndrome is a rare genetic disease caused by mutations (changes) in three genes that tell certain parts of your child's body how to grow. As a result, parts of your child's kidneys, ears and eyes do not grow correctly.
Alport syndrome always causes kidney disease and can also cause hearing loss and eye problems. Your child may start to have symptoms in early childhood. There are treatments that can help protect your child's kidneys and help them work well for longer.
Autosomal recessive polycystic kidney disease (ARPKD)
Autosomal recessive polycystic kidney disease (ARPKD) is one type of polycystic kidney disease (PKD). ARPKD is the less common type. It causes cysts to form in your child's kidneys and liver. Cysts are sacs filled with fluid. The cysts damage your child's kidneys' tissues and make them much larger than they should be.
Babies may have symptoms before they are born that a doctor can see on an ultrasound. It can cause life-threatening problems in babies, such as kidney failure. Doctors treat the symptoms of ARPKD, such as with medicines. Doctors also treat any problems caused by ARPKD, such as urinary tract infections.
Nephropathic cystinosis is the most common type of cystinosis. Cystinosis is a rare genetic disease that causes cystine to build up in your child's cells. Cystine is a building block of protein. Too much cystine can damage their organs including their kidneys and eyes.
Your child may start to have symptoms in early childhood. Doctors treat cystinosis with medicines, such as medicines to prevent cystine from building up. If untreated, it can lead to kidney failure.
What is a kidney infection?
An infection happens when bacteria or a virus enters your child's body and causes an illness. Many infections are treated with antibiotics and do not cause any long-lasting damage. However, sometimes infections can lead to an inflammatory response that damages the kidneys, leading to:
- Hemolytic uremic syndrome (HUS)
- Interstitial nephritis
Glomerulonephritis attacks the tiny filters in your child's kidneys that clean their blood (glomeruli). You may also hear it called glomerular disease. When the glomeruli are damaged, they cannot remove waste and fluid from your child's body like they should. Your child may get glomerulonephritis suddenly or slowly in time.
Causes of glomerulonephritis include:
- Streptococci bacteria (the bacteria that causes strep throat)
- Bacterial infection in your child's heart
- Viral infections like HIV, hepatitis B and hepatitis C
Doctors treat the cause of glomerulonephritis, such as an antibiotic to treat a strep throat infection.
Hemolytic uremic syndrome (HUS)
Hemolytic uremic syndrome (HUS) is a rare disease that happens when damaged red blood cells block your child's kidneys' filters. It can cause kidney damage and failure.
Infection with E. coli bacteria is the most common cause of HUS. E. coli is a group of bacteria that is normally in your large intestine, but can cause infection when spread through contaminated food, such as meat and dairy. Doctors usually treat HUS in the hospital.
HUS caused by E. coli is the leading cause of sudden kidney failure in children.
Interstitial nephritis is a disease that causes inflammation (swelling) around parts of your kidneys' filters called the tubules. This inflammation lowers your kidneys' ability to clean your blood and make urine (pee). There are two kinds of interstitial nephritis:
- Acute interstitial nephritis, which lasts a short time. This is the most common type of interstitial nephritis.
- Chronic interstitial nephritis, which lasts longer: weeks, months or years.
Without treatment, interstitial nephritis can cause kidney damage or kidney failure.
EBV, CMV (also caused by medications like NSAIDs which are used to treat fever)
What is nephrotic syndrome?
Nephrotic syndrome is a group of symptoms that show that your child's kidneys are not working as well as they should. The symptoms include:
- Too much protein in their urine
- Not enough protein in their blood
- Too much fat or cholesterol in their blood
- Swelling in their legs, feet, ankles and sometimes face and hands
Your child may start to have symptoms between ages two and six.
What are systemic diseases that cause kidney disease?
A systemic disease is a disease that affects many organs or your child's whole body, not just one organ or body part. Systemic diseases that cause kidney disease include:
- Autoimmune disorders such as Lupus
Diabetes is a lifelong disease where your child's blood sugar (glucose) is too high. Children can get type 1 and type 2 diabetes. Diabetes is not a common cause of kidney disease in children. This is because it takes many years for high blood sugar from diabetes to damage their kidneys and cause kidney disease.
Although it takes many years, high blood sugar from diabetes damages the tiny blood vessels in their kidneys called glomeruli. These blood vessels clean their blood. When the glomeruli are damaged, they cannot filter their blood like they should and this can cause kidney disease.
If your child has diabetes, talk with their doctor to control their blood sugar and keep it in a healthy range. This is the main way to prevent diabetes from causing kidney disease.
Learn more about diabetes.
Lupus is an autoimmune disease that causes your child's immune system to attack healthy cells in their body. This causes pain, swelling and damage to all parts of their body, including their kidneys.
Doctors treat lupus with medicines, such as a medicine called an immunosuppressant. Immunosuppressants are medicines that lower or stop your immune system's response, so it does not harm the kidneys as much. However, lupus can cause permanent kidney damage and kidney failure.Learn more about lupus nephritis.
What is kidney trauma or injury?
Kidney trauma or injury is damage to your child's kidneys that can cause sudden kidney failure. Trauma or injury can cause a severe drop in your child's blood pressure, which means their kidneys get less blood. This can damage the kidneys and cause them to stop working suddenly. Examples of trauma or injury include:
- A severe physical injury, such as a hit directly to their kidneys or an object that goes through their skin
- Dehydration (not enough water in their body)
- Bleeding too much
- Medication injury (antibiotics, NSAIDs, some immunosuppressant medications)
If your child has a trauma or injury, such as a hit to their body or head, take them to the Emergency Room right away. You may not be able to see or know about trauma that happens inside their body.
What are problems with the urinary system?
The urinary system is the organs that make urine (pee) and remove it from your child's body. It includes the kidneys, ureters, bladder and urethra. Urine travels from their kidneys through two thin tubes called the ureters, into the bladder and then out of their body through their urethra. Two problems in the urinary system can cause kidney disease:
- A blockage in the urinary system
- Urine reflux
A blockage in the urinary system
A blockage means that one or both of your child's ureters is blocked and urine cannot flow through to their bladder. This prevents urine from moving out of their body. Urine can build up in their kidneys and cause kidney damage or kidney failure.
Sometimes a blockage will go away on its own and other times doctors may do surgery to fix it.
Urine reflux happens when urine flows from your child's bladder back up to their kidneys. Normally, urine flows only one way: from the kidneys to the bladder. When the valve-like mechanism in the bladder does not work and does not completely shut then urine can move backwards — from the bladder back up to the kidneys. In time, this reflux can make urine build up in the kidneys and cause kidney damage or kidney failure.
In certain cases, antibiotics may be needed to prevent infection that can occur because of the reflux. Sometimes reflux goes away on its own, sometimes it can be treated with an injection called "deflux," but sometimes surgery is needed.
What are the most common causes of kidney failure in children?
The most common causes of kidney failure differ based on your child's age:
- From birth to age four, the most common causes are kidney birth defects and genetic diseases
- From ages five to 14, the most common causes are genetic diseases, nephrotic syndrome and systemic diseases
- From ages 15 to 19, the most common causes are problems with the glomeruli, such as nephrotic syndrome and lupus
How doctors test for kidney diseasein children.
Treatments for kidney failure in children.