Kidney stones can quietly form in the urinary tract, often without any immediate signs or symptoms. These solid crystals develop when certain substances in the urine combine, and the type of stone that forms depends on the specific composition of the urine.

“About one in 10 people will have a kidney stone in their lifetime,” said Kyle Wood, M.D., associate professor in the UAB Department of Urology. “Most people have calcium oxalate kidney stones. When the stone starts to move out of the kidney into the ureter, the tube that connects the kidney to the bladder, this is when people experience significant pain.”

While many people recognize kidney stone disease only when pain strikes, it’s important to understand that the disease can have subtle, silent signs that go unnoticed. Identifying these early symptoms is crucial for preventing complications and managing kidney stone disease effectively.

Dr. Wood discusses the subtle signs of kidney stone disease, preventative measures, and treatment and removal options available at UAB.

Silent signs

Most people experience significant pain when a stone enters the ureter. However, because it is so narrow, even small stones can become lodged there. When this happens, the urine backs up in the kidney, leading to intense pain often accompanied by nausea and vomiting. Until the stone passes, severe discomfort is common.

“Stones in the kidney that aren’t causing a blockage may also result in pain, though sometimes people experience no pain at all,” Wood said. “In these cases, the first noticeable symptom might be blood in the urine (sometimes microscopic) or recurrent urinary tract infections.”

Risk factors

Kidney stone disease is closely associated with various health conditions, including obesity, diabetes, hypertension, and heart disease. Lifestyle factors, particularly dietary habits, are major contributors to the development of kidney stones. Alabama is part of the Kidney Stone Belt, a section of the country that has higher prevalence of kidney stones.

“People who are dehydrated or don’t drink enough fluids are at increased risk,” Wood said. “If your diet is high in sodium (salt) or high in protein, that can also increase your risk. Not eating enough fruits and vegetables can raise your risk as well.”

Genetics also contribute to kidney stone disease, as it often runs in families. People with a family history of kidney stones may have a higher chance of developing them themselves.

Preventative measures

Staying hydrated is the most important step in preventing kidney stones. Unless limited by a medical condition, aim for around 3 liters (or 96 ounces) of fluid intake daily to keep the kidneys well-flushed. Reducing salt is also essential—read food labels carefully and try to avoid high-sodium options, particularly processed foods, which are often loaded with salt.

“Keeping your sodium intake below 2,000 mg per day is ideal,” Wood said. “Additionally, a balanced diet rich in fruits, vegetables, and normal protein levels supports overall kidney health. Regular exercise and maintaining a healthy weight can further reduce the risk of kidney stones and improve overall wellness.”

Treatments available at UAB

UAB houses a comprehensive kidney stone clinic that takes a personalized approach to patient care, conducting metabolic and dietary evaluations for everyone. The clinic specializes in kidney stone surgeries, with world-renowned surgeons leading the field. UAB focuses on stone disease as a chronic disease that warrants a thorough and thoughtful workup and individualized treatment plan.

In addition to its clinical expertise, UAB is at the forefront of kidney stone research, with an extensive portfolio aimed at advancing the understanding and treatment of stone disease. The Kidney Stone Group and Clinic is also recognized as a Oxalosis and Hyperoxaluria Foundation Care Center, further emphasizing UAB’s leadership in treating various kidney stone conditions.

“We are one of only three institutions to hold this designation, and we are recognized for our expertise in treating rare kidney stone diseases,” Wood said. “Our comprehensive multidisciplinary program is dedicated to evaluating and managing both common and rare kidney stone conditions.”

Kidney stone removal

When kidney stones aren’t obstructing the kidney, causing symptoms, or presenting any risk of harm, monitoring them is often the best approach. However, when a stone is blocking the kidney, is large or numerous, or leads to discomfort and other symptoms, intervention becomes necessary.

“Sometimes, this intervention involves medication to support the body in passing the stones naturally, easing the process and managing pain,” Wood explained. “In other cases, surgical removal may be required to prevent complications and alleviate symptoms.”

There are three primary surgical methods used for stone removal, each with its own approach and benefits.

Shockwave lithotripsy 

Shockwave lithotripsy uses energy generated outside the body, which is directed at the stone to break it into smaller fragments.

“The success of this procedure depends on factors like the stone's composition, its location, and the patient's body type,” Wood said. “One key advantage of this method is that it often doesn’t require inserting cameras into the body or placing a ureteral stent. Additionally, the procedure carries a low risk of complications.”

Ureteroscopy and stone removal

Another widely used option is ureteroscopy with stone removal. This procedure involves using small cameras that are inserted into the urinary tract to locate the stone.

“Once the stone is found, lasers and baskets are used to break it apart and remove it,” Wood said. “While success rates are generally high, patients often require a ureteral stent afterward to aid in the healing of the urinary tract. However, these stents can be quite uncomfortable for the patient.”

Percutaneous nephrostolithotomy

For larger stones or in cases of complex anatomy, surgeons may perform percutaneous nephrostolithotomy.

“This procedure involves surgery through the back, using small cameras to access the kidney,” Wood said. “It is more invasive and carries a higher risk compared to other methods.”

While shockwave lithotripsy and ureteroscopy are typically outpatient procedures, percutaneous nephrostolithotomy usually requires an overnight hospital stay for recovery.

Long-term management

Managing kidney stone disease long-term can be challenging, especially when it involves daily medications or significant changes to dietary habits. These lifestyle adjustments are often essential to reduce the risk of future stone formation.

“Unfortunately, once a person has experienced a kidney stone, they are at a higher risk of developing another within the next five to 10 years,” Wood said. “This makes prevention a crucial focus in the management of kidney stone disease.”

By adhering to a tailored treatment plan and making the necessary lifestyle changes, patients can significantly reduce the likelihood of recurrent stones and better manage their condition over time.