Kidney Stones

If you’ve ever had a kidney stone, it’s not something you’re likely to forget. Passing a kidney stone is a painful experience. The reason why kidney stones form is not entirely clear. But it happens in many adults, and there are ways to help treat and prevent them.

How Kidney Stones Form

Each person has two kidneys. Your kidneys make urine by removing water, waste, sugar, and many other kinds of substances from your blood. The urine moves from your kidneys to your bladder through two tubes called the ureters. Your bladder stores the urine until it leaves your body through another tube called the urethra.

Your urine can contain many kinds of chemicals. These include calcium, oxalate, and phosphate. Sometimes one or more of these chemicals can clump together and form crystals. Normally, urine also contains chemicals that keep crystals from forming. But in some people, crystals still form. Sometimes, the crystals grow larger and become stones. They can be as small as a grain of sand or as large as a pearl -- or even a golf ball.

A crystal or small stone may pass out of the body without being noticed. But a larger stone may stay in your kidney or become stuck in a ureter, the bladder, or the urethra.


A stone that is stuck often causes a sharp, cramping pain in your back, side, or lower abdomen. There may be blood in your urine. You may have nausea and vomiting. You may need to urinate often, and there may be a burning feeling when you urinate. Sometimes the stone causes an infection, which can cause fever and chills. Other times, a stone may cause only an ache in the groin. Or the stone may cause few symptoms until there is an infection.


Your healthcare provider will ask about your medical history and give you a physical exam. You may have urine tests or blood tests. Your healthcare provider may recommend other tests to see if you have a kidney stone. Common tests include an ultrasound of the kidney. Ultrasound uses sound waves to create images of the kidney on a computer. You may also have a computed tomography, or C-T scan. A C-T scan creates a picture of your body from the kidneys to the bladder with a series of X-rays put together by a computer.

Another test is called a kidney-ureter-bladder, or K-U-B, X-ray. This X-ray shows the size and position of the stone.


The treatment of a kidney stone depends on the location and size of the stone. While a small stone may pass on its own over 24 to 48 hours, a larger stone might need to be treated.

One treatment is called shockwave lithotripsy  therapy. It uses a machine to send strong sound waves into a small part of the body. The sound waves, or shockwaves, can break a larger stone into smaller stones that can pass more easily.

Another treatment is ureteroscopy. It is done with a thin, flexible tool called a ureteroscope. A wire with a camera attached is passed up through the bladder to the ureter. The stone is found and removed.

A stone can also be removed with percutaneous nephrolithotomy. This uses a small incision in a person’s back to find and remove the stone.


One way to help keep kidney stones from forming is to drink more water throughout the day.

Your healthcare provider may recommend some changes in your diet. You may need to eat less sodium, meat, and dairy foods. And you may be given medication to help keep stones from forming.

What We Have Learned

  1. Kidney stones always cause pain. True or false?
    The answer is False. Small stones may pass without being noticed.

  2. There is nothing you can do to prevent kidney stones. True or false?
    The answer is False. There are steps you can take to prevent kidney stones, such as drinking more throughout the day.

  3. A large kidney stone has to pass on its own. True or false?
    The answer is False. There are treatments for kidney stones, including breaking them into smaller stones or removing them.