A stone in your kidney is an irregularly-shaped solid mass or crystal that can be as small as a grain of sand up to the size of a golf ball. Depending on the size of your kidney stone (or stones), you may not even realize that you have one. Even small stones can cause extreme pain as they exit your body through your urinary tract. Drinking fluids may help the process, which can take as long as three weeks.
A large kidney stone can get trapped in your ureter (the tube that drains urine from your kidney down to your bladder). When this happens, the stone can cause bleeding and keep urine from leaving your body. You may need surgery for a stone that can’t pass on its own.
Researchers have concluded that about one in ten people will get a kidney stone during their lifetime. Kidney stones in children are far less common than in adults but they occur for the same reasons. They’re four times more likely to occur in children with asthma than in children who don’t have asthma.
White men in their 30s and 40s are most likely to get kidney stones. However, anyone can develop kidney stones.
There are several risk factors for developing kidney stones. These include:
Certain medical conditions can also increase your risk of developing stones. This is because they may increase or decrease levels of the substances that make up a kidney stone. These conditions can include:
Some medications can increase your risk of developing a stone. These medications include:
Certain foods can also place you at risk of a kidney stone. These foods include:
You can have kidney stones for years without knowing they’re there. As long as these stones stay in place within your kidney, you won’t feel anything. Pain from a kidney stone typically starts when it moves out of your kidney. Sometimes, a stone can form more quickly — within a few months.
Talk with your healthcare provider about your risk factors. They might do a 24-hour urine test to check how quickly you develop stones.
The most common type of kidney stone is a calcium oxalate stone. This type happens when calcium and oxalate combine in your urine. It can happen when you have high quantities of oxalate, low amounts of calcium and aren’t drinking enough fluids.
Stones caused by uric acid are also fairly common. These come from a natural substance called purine, which is a byproduct of animal proteins (meat, chicken and fish).
The materials that make up a kidney stone can be different. You could develop a calcium oxalate stone and one made of uric acid.
Kidney stones are formed from substances in your urine. The substances that combine into stones normally pass through your urinary system. When they don’t, it’s because there isn’t enough urine volume, causing the substances to become highly concentrated and to crystalize. This is typically a result of not drinking enough water. The stone-forming substances are:
You can have a stone in your kidney for years and not know it’s there. But, when it starts to move or becomes very large, you may have symptoms. Symptoms of a kidney stone include:
Smaller kidney stones may not cause pain or other symptoms. These “silent stones” pass out of your body in your urine.
The most common symptoms of kidney stones are blood in the urine or pain. The amount of pain your child experiences and where it hurts depends on where the stone is located and its size. Other symptoms include:
Most pediatric kidney stones remain in the kidney, but up to a third may migrate from the kidney and get stuck in a ureter. Stones that remain in the kidney, although often painless, can be the source of recurrent urinary tract infections. Those that lodge in the ureter can create severe colicky pain.
Your healthcare provider will discuss your medical history and possibly order some tests. These tests include:
Once diagnosed, your healthcare provider will first determine if you even need treatment. Some smaller kidney stones may leave your system when you urinate. This can be very painful. If your provider decides that you do need treatment, your options include medications and surgery.
Medications. Medications may be prescribed to:
You should ask your healthcare provider before you take ibuprofen. This drug can increase the risk of kidney failure if taken while you’re having an acute attack of kidney stones — especially in those who have a history of kidney disease and associated illnesses such as diabetes, hypertension and obesity.
Surgery. There are four types of surgeries used to treat kidney stones. The first three are minimally invasive, meaning that the surgeon enters your body through a natural opening (like your urethra), or makes a small incision.
Most children’s kidney stones can be treated with the shock wave lithotripsy (SWL), a completely non-invasive procedure. Your child is placed under anesthesia and sound waves of specific frequencies are focused on the stones to shatter them into fragments small enough to be easily passed during urination.
The amount of time it can take for you to pass a kidney stone is different from another’s. A stone that’s smaller than 4 mm (millimeters) may pass within one to two weeks. A stone that’s larger than 4 mm could take about two to three weeks to completely pass.
Once the stone reaches the bladder, it typically passes within a few days, but may take longer, especially in an older man with a large prostate. However, pain may subside even if the stone is still in the ureter, so it’s important to follow up with your healthcare provider if you don’t pass the stone within four to six weeks.
There are three liquids rumored to help with kidney stones:
Avoid soda and other drinks with added sugar or fructose corn syrup. They increase your risk.