What is a Kidney Stone?

Q: What is a kidney stone?

A: Kidney stones are small, hard deposits that form inside your kidneys. Passing kidney stones can be quite painful, but the stones usually cause no permanent damage. Most people just take pain medication and drink lots of water to pass a kidney stone. In other instances, surgery may be needed. A doctor will help determine the course of treatment and will talk about preventative treatment to reduce the risk of recurrent kidney stones for those with an increased risk of developing them again.

Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute. At the same time, your urine may lack substances that keep crystals from sticking together, creating an ideal environment for kidney stones to form.

Symptoms may not be evident until the kidney stone moves around within the kidney or passes into the ureter, which is the tube connecting the kidney and bladder. Symptoms include:

  • Severe pain in the side and back, below the ribs
  • Pain that spreads to the lower abdomen and groin
  • Pain that comes in waves and fluctuates in intensity
  • Pain on urination
  • Pink, red or brown urine
  • Cloudy or foul-smelling urine
  • Nausea and vomiting
  • Persistent urge to urinate
  • Urinating more often than usual

Blood and urine tests and imaging tests will help determine if a kidney stone is present. A doctor may also analyze the kidney stones to determine what is in it and how to prevent more.

Lifestyle changes may be needed to reduce the risk of kidney stones. Drink plenty of water. If you tend to form calcium oxalate stones, which is the most common type, restrict foods rich in oxalates such as beets, spinach, sweet potatoes, nuts, tea, chocolate and soy products. Choose a diet low in salt and animal protein. Continue eating calcium-rich foods, but use caution with calcium supplements. Since adequate calcium intake is also important for bone health, talk to your doctor if there are any concerns about calcium intake.

Today’s expert is Renae Schuler, MD, ThedaCare Physicians-New London