Kidney stones are small, hard deposits of mineral and acid salts formed within the urinary tract, which can block the drainage of urine and cause deep pain, sometimes nausea, and vomiting. Although kidney stones are still relatively uncommon in children, the number of cases is growing.
Types of Kidney Stones in Children
Kidney stones form when large amounts of substances like salt accumulate in the kidneys, eventually turning into a stone or crystals. Other diseases cause certain stones, but many of them are formed because of diet and nutrition issues. Some doctors suspect that more children may be getting this condition due to too much salt in their diets. Your child will be tested to measure their uric acid levels.
Some types of kidney stones include:
- Calcium stones are caused by too much salt.
- Cystine stones can form in people who have cystinuria, an inherited disorder that’s marked by an increased formation of stones in the kidney, bladder, and ureter.
- Struvite stones are most commonly caused by urinary tract infections.
- Uric acid stones can occur after chemotherapy or with gout.
Symptoms of Kidney Stones
Kidney stones affect children in different ways. Symptoms vary from stones that cause no pain (stones that are still in the kidney and have not moved to the ureter) to stones that cause urinary obstruction, resulting in severe pain. Common symptoms of kidney stone disease include:
- Pain in the abdomen, side, back, or groin
- Blood in the urine
- Frequent urination
- Nausea and/or vomiting
Any child experiencing pain and has blood in their urine should be evaluated by a doctor even if it's just a little bit.
Cause of Kidney Stones
Kidney stones form when there is too much mineral (such as salt) in the child’s body and not enough water in their urine, often as a result of dehydration.
Some rare genetic conditions can cause the child’s body to make kidney stones. If there is a family history of stones, it makes it more likely that other people in the family may experience kidney stones.
Children who don’t or can’t move for extended periods due to surgery or other complications may be more likely to experience kidney stones. This happens because when the child’s bones are inactive, they’re unable to regenerate themselves, resulting in the mineral calcium getting flushed into their system.
Risk Factors for Kidney Stones in Children
The underlying causes of most kidney stones in children are a urinary metabolic abnormality, urinary tract infection, and/or structural kidney or urinary tract abnormalities. Also, diet, genetics, and lifestyle can all contribute to kidney stones.
Metabolic disorders. If your child has a condition or disorder that prevents their body from properly breaking down food, it can lead to high levels of oxalate and cystine in the urine, which leads to stone formation.
Congenital anomalies of kidney and urinary tract. If your child hasCAKUT, this group of abnormalities affecting the kidneys or other structures of the urinary tract may lead to the development of kidney stones.
Loss of fluids (dehydration). If your child does not drink enough fluids, their urine can become concentrated and dark. When there is not enough fluid to dissolve minerals normally, it increases the likelihood that crystals or kidney stones will form.
Diet. The kinds of food your child eats can affect their chances of getting kidney stones. Foods high in protein can cause acid in the body to increase, which lessens the amount of urinary citrate (a chemical that helps to prevent kidney stones). Without enough urinary citrate, kidney stones are likely to form.
Another risk factor is a high-salt diet. When there is a large amount of salt passing through the urine, it can pull calcium along with it, increasing the chance of kidney stones forming. Eating oxalate-rich foods such as tea, chocolate, or leafy green vegetables may make things worse.
A family history of stones. If a family member (such as a parent or sibling) has had kidney stones, it greatly increases the chance of the child experiencing kidney stones.
Diagnosing Kidney Stones in Children
Your child’s doctor will run a variety of tests to determine if kidney stones are present. They may do:
- Urinalysis
- Abdominal CT scan
- Abdominal/kidney MRI
- Abdominal X-ray
- Kidney ultrasound
Once a stone is found, the doctor will analyze it to determine what type of kidney stone it is.
Treatment for Kidney Stones in Children
Most kidney stones pass through the body’s urinary tract on their own and eventually leave the child’s system. Pain relievers can be used to help manage the pain. If the kidney stones caused a urinary tract infection, antibiotics may be given.
In some cases, your doctor with refer your child to a specialist. They may give your child medication to help you pass the kidney stone. Medications known as alpha blockers relax the muscles in your ureter, helping you pass the kidney stone more quickly and with less pain. You may be asked to strain the urine.
If your child has a very large kidney stone that doesn’t pass with dietary changes or medication, your doctor may recommend surgery. This typically involves a surgery where the doctor makes a small incision in your back and inserts small telescopes and instruments to remove the stones. For a procedure like this, they are given general anesthesia (a medicine that puts them in a sleep-like state).