Skip to content
My WebMD Sign In, Sign Up

Kidney Stones Health Center

Font Size
A
A
A

Kidney Stones - What Happens

A kidney stone begins as a tiny piece of crystal in the kidney. When the urine leaves the kidney, it may carry the crystal out, or the crystal may stay in the kidney. If the crystal stays in the kidney, over time more small crystals join it and form a larger kidney stone.

Most stones leave the kidney and travel through the urinary tract camera.gif when they are still small enough to pass easily out of the body. No treatment is needed for these stones.

Larger stones may become stuck in the tubes that carry urine from the kidney to the bladder (ureters). This can cause pain and possibly block the urine from flowing to the bladder and out of the body. The pain often becomes worse over 15 to 60 minutes until it is severe. The pain may ease when the stone no longer blocks the flow of urine. And the pain often goes away when the stone passes into the bladder. Medical treatment is often needed for larger stones.

Problems that may occur with kidney stones include:

  • An increased risk of urinary tract infection, or making an existing urinary tract infection worse.
  • Kidney damage, if stones block the flow of urine out of both kidneys (or out of one kidney, for people who have a single kidney). For most people with healthy kidneys, kidney stones do not cause serious damage until they completely block the urinary tract for 2 weeks or longer.

Kidney stones are more serious for people who have a single kidney or an impaired immune system or have had a kidney transplant.

Stones in pregnant women

When stones occur during pregnancy, an obstetrician and urologist should determine whether you need treatment. Treatment will depend on your trimester of pregnancy.

Next Article:

WebMD Medical Reference from Healthwise

Last Updated: May 02, 2013
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

Today on WebMD

Kidney Stone
SLIDESHOW
5 Signs You Might Have A Kidney Stone
Article
 
Lots Of Water Part Of Kidney Stone Treatment
Article
Research To Prevent Kidney Stones Under Way
VIDEO
 

Thumbnails Kids Get Kidney Stones Too
VIDEO
Food And Drink To Keep Away Kidney Stones
Article
 
What Is A Kidney Stone Made Of
Article
7 wonders of Water Slideshow
SLIDESHOW