Kidney Stones

Kidney stones are deposits of mineral salts, called calculi, in the kidney. These stones can pass into the ureter, the narrow tube that connects the kidneys to the bladder.

What is going on in the body?

Kidney stones occur when the urine has a high level of minerals that form stones. Most kidney stones are made from calcium. Minerals such as uric acid and oxalate may also form stones. These stones can irritate kidney tissue and block urine flow.

What are the causes and risks of the condition?

Kidney stones are caused by an accumulation of mineral salts, with calcium being the most common. People with kidney stones may first have dysfunction or damage to some of the collecting tubes in the kidney. Factors that increase the risk of stone formation include the following:

What are the signs and symptoms of the condition?

Some stones can grow to be very large without causing symptoms. Flank pain is a common symptom of kidney stones. Flank pain occurs on one side of the back near the lower ribs. If stones have passed into the ureter, the person may have groin pain. Pain may also radiate down the lower side of the abdomen. A kidney stone may cause blood in the urine, nausea, and vomiting.

How is the condition diagnosed?

Diagnosis of kidney stones begins with a medical history and physical exam. The healthcare provider may order tests, including:

What can be done to prevent the condition?

Maintaining a high fluid intake is the most important step an individual can take to avoid this problem. People with a history of kidney stones should drink enough fluid to produce at least 2 liters, or about 2 quarts, of urine each day.

What are the long-term effects of the condition?

Serious complications are unusual. Most urinary stones require treatment simply because of the intense pain that the stones cause. Following are some of the serious complications of kidney stones:

What are the risks to others?

Kidney stones are not contagious and pose no risk to others.

What are the treatments for the condition?

There are medical and surgical components to the treatment of kidney stones. Medical care is first directed toward managing pain or infection. Afterward, treatment is directed at preventing more stones from forming. Mineral levels in the urine are sometimes measured by analysis of a 24-hour collection of urine. This information is used to determine the steps needed to prevent future stones. These may include dietary changes or medication.

Many stones will pass on their own. People are often given pain medication and told to drink a lot of fluids. They are then observed for a day or two to see if the stone passes. If the stone is very large on X-ray or doesn't pass, further treatment is needed.

Some types of stones can be dissolved with oral medications. Stones containing calcium cannot be dissolved using medication. If this type of stone does not exit the body on its own, some other treatment is required.

One type of treatment is lithotripsy, which uses shock waves aimed at the kidney stones from outside the body. The shock waves often break up the stones into small pieces. The small pieces can then be passed out of the body in the urine.

Surgery may be needed to remove the stone or stones. There are several surgery options. One method involves removing stones through a small, lighted tube called an endoscope. The endoscope can be passed through the urethra into the body. The urethra is the tube that carries urine out of the body. The endoscope can then be advanced into the bladder or ureters to see the stone. The stone can then be removed through the endoscope.

Another type of endoscope is larger. It is inserted directly into the kidney through the skin of the abdomen. Larger stones can be removed this way. The majority of stones can be treated with one of these methods. If not, traditional or open surgery may be needed.

What are the side effects of the treatments?

Pain medications may cause drowsiness, constipation, or allergic reactions. Surgery may cause bleeding, infection, or allergic reaction to anesthesia. Several of the medications used to prevent further stone formation may cause stomach or bowel upset.

What happens after treatment for the condition?

If stones pass on their own or are removed, a person can usually return to normal activities. Prevention of future stones is stressed. The person will be advised to drink plenty of fluids every day. Medications are helpful in some cases to prevent further stones.

How is the condition monitored?

People may be checked periodically with regular or special X-ray tests to see if stones are forming again. If a surgical procedure was difficult or complicated, additional X-ray tests may be used to check for urinary tract blockage. Any new or worsening symptoms should be reported to the healthcare provider.

Author:Stuart Wolf, MD
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:06/30/01
Reviewer:Eileen McLaughlin, RN, BSN
Date Reviewed:05/22/01