Kidney stones can be one of the most painful disorders experienced by men and women. In fact, some women have stated that kidney stones are more painful than childbirth.

Kidney stones have affected many famous people, including Benjamin Franklin, Francis Bacon, Isaac Newton, and Peter the Great. The incidence of kidney stones is very high in the southeastern part of the United States, garnering the region the nickname "Stonebelt."

New technology has greatly improved the surgical methods of stone removal. In addition, improved medical treatments can help prevent recurrent kidney stone formation.

The specialists at the Duke Comprehensive Kidney Stone Center provide expert care for patients with kidney stone disease.

Read a glossary of kidney stone terms

Understanding Kidney Stones

The urinary tract consists of the kidneys, the bladder, and the tube connecting the kidneys to the bladder (kidney tube or ureter) and the tube that allows you to empty the bladder (urethra).

The kidneys act as the body's filtering system. They constantly screen the blood, absorbing the good chemicals and eliminating the unwanted chemicals in our urine. Urine then passes from the kidney, down the kidney tube, into the bladder, and eventually out of the body via the urethra.

If certain chemicals or minerals buildup in the kidneys, they can form a stone. Stones may stay in the kidney or they can travel down the urinary tract, through the ureter, causing severe pain.

The size, shape, and location of the stone will determine the symptoms that one may experience and will define the most appropriate treatment for stone removal.

Causes of Kidney Stones

Many factors may play a role in kidney stone formation, such as age, gender, a family history of stones, the amount of daily fluids consumed, occupation, climate, urinary tract infection, associated medical problems (such as bone disease), and dietary patterns.

Usually, males suffer from kidney stones more commonly than females, and African Americans tend to have far fewer stones than Caucasians, although recent studies have documented an increasing incidence of stones in women and non-Caucasians. Hereditary diseases such as renal tubular acidosis, cystinuria, and hyperoxaluria can cause stone formation as well.

One of the more common and important causes of kidney stone formation is not drinking enough fluids. A reduced fluid intake increases the concentration of stone forming components within the urine, thereby increasing the risk of stone formation.

Determining the chemical composition of the stone and performing analysis of the urine and blood will help your doctor to determine what is causing new stone formation and how to prevent repeat stone formation.

Symptoms of Kidney Stones

Kidney stones may cause all or only a few of the following symptoms:

• Excruciating pain; typically in the back, side, lower abdomen, or groin
• Blood in the urine
• A burning sensation during urination
• Difficulty urinating
• Frequent urination
• Fever or chills
• Nausea or vomiting
• Loss of appetite

Diagnosis of Kidney Stones

Many different conditions can produce symptoms similar to kidney stones. In order to definitively diagnose kidney stones, and their possible effects on the body, a number of investigations are helpful.

A thorough medical history and physical examination performed by a medical professional is essential. The urine is checked for the presence of blood (associated with over 90 percent of stones), which may be so small that the blood in the urine can only be seen by a microscope.

The urine is also checked for the presence of infection, which can be associated with kidney stones and potentially be very serious. The patient’s blood is checked to ensure that overall kidney function has not been significantly affected and that there is no infection in the blood stream.

Special imaging tests can be used to locate and determine the size of kidney stones. X-rays, ultrasound, and CT scans are all potential ways of diagnosing kidney stones; the decision on which one to use will depend on a number of factors, and is best made by a medical professional.

Treatment of Kidney Stones

Duke's team of urologists has experience in a number of treatment options to remove kidney stones, including minimally invasive surgical procedures.

Surgical management: Read about surgical treatment for kidney stones available at Duke.

Non-surgical management: Not all kidney stones are diagnosed because of symptoms. Some people have kidney stones diagnosed during the investigation of other non-related medical issues.

If a kidney stone is relatively small, is not causing any pain, is not in danger of blocking the kidney tube, or other medical issues make treatment of the stones challenging, a decision can be made to just observe the stone or wait until it is safe to treat the stone. This decision is best made by a specialist who is familiar with treating kidney stones.

Important in this decision is making sure the factors contributing to stone formation have been determined and treated satisfactorily with an adequate fluid intake and appropriate medications.