Passing a kidney stone. Women have compared it to the pain of child birth. Men have described it as the worst pain in their life. Kidney stones often cause excruciating pain originating from deep inside your right or left side or back. The telltale shooting, stabbing pain can start as a single stone passes through one of the tubes from the kidney to the bladder (ureter), or from the bladder to the outside of the body (urethra).
How do kidney stones form?
A kidney stone is made up of hard minerals and salts that form microscopic crystals. Normally, the minerals and salts are diluted in urine. If urine becomes too concentrated (not enough water), crystals stick together and become visible stones. Most kidney stones are made of calcium oxalate. They could also be made of other substances, such as uric acid.
Why do kidney stones cause pain?
The kidneys filter out the liquid waste, collect it, then send it down two tubes (ureters) to the bladder. Most kidney stones are tiny, and pass through the ureters through the urethra and out of the body unnoticed. But when larger stones pass, they can stretch the ureter and can cause severe pain. If large enough, a kidney stone can get stuck and block the flow of urine. Problem kidney stones can range from the size of a pebble to as large as a pearl. Rarely they can even become the size of a golf ball.
What are the symptoms?
Symptoms of a kidney stone can occur off and on over a few days or longer, for as long as it takes to pass.
Call the doctor if you have severe pain on your side, back, belly or groin, or urine that looks pink or red.
Other symptoms may include:
- Nausea and vomiting
- Pain when you urinate
- Urine that is cloudy or smells bad - if there is also an infection
How are kidney stones treated?
You may be able to pass a kidney stone by drinking lots of water. If the pain is severe, your doctor may refer you for emergency treatment for pain management. If it's not possible to drink enough fluids, your doctor may give you fluids through a vein to help pass a stone. You may be given antibiotics if there is also a urinary tract infection. If the stone is too big to pass on its own, a procedure may be needed to remove the stone, such as:
- Lithotripsy. Sound waves are aimed at the kidney stone to break it up. Smaller pieces of the stone can then pass through the ureter.
- "Tunnel" surgery. An incision is made into the back and into the kidney. A special instrument is used to remove the stone directly.
- Ureteroscope. A thin tube is inserted into the urethra (where urine exits the body), into the bladder and up the blocked ureter. The stone is removed through a tiny cage attached to the scope.
What are risks for kidney stones?
Not drinking enough water can lead to kidney stones. They can also form due to genetic (inherited) disorders. If you have formed a stone before, there is a chance it will happen again.
How can I prevent kidney stones?
- Drink plenty of water (eight to 10 glasses a day), unless your doctor tells you otherwise. Water helps to keep urine diluted and prevent stone-forming salts and minerals from clumping together.
- Reduce your intake of salt. Cutting salt in your diet helps to lower the amount of salt in the urine. Don't add salt to your food, and avoid salty foods such as processed meats.
- Get enough calcium in your diet. Earlier studies recommended calcium restriction in people with kidney stones. But later studies showed that getting the right amount of calcium for your age may reduce stone formation.
- Avoid excessive amounts of vitamin C (limit vitamin C to 2 grams/day). Vitamin C can increase oxalate in the urine, which can lead to stone formation.
