What are the first signs of kidney stones?

Kidney stones, also called renal calculi, are solid deposits of chemicals and crystals that form in one or both kidneys.

Here, Mr Matthew Liew, experienced consultant urologist, provides a detailed insight into kidney stones. He discusses the symptoms of kidney stones, how kidney stones are removed, and if kidney stones can be a sign of cancer, among other important points.

What do kidney stones feel like? Are they noticeable?

People who have ‘stable’ kidney stones may only have a mild ache. Many people who have had a kidney stone recall that it is incredibly painful, describing it as “the worst pain ever”. Despite this, there is a small minority of lucky people who pass kidney stones without having any symptoms.

Kidney stone pain tends to feel like it is coming in waves; this is called a renal or ureteric colic, depending on the location of the stone in the urinary tract. Typically, the colic is on one side (where the kidney stone is moving) and can radiate to the groin area. During the colic episode, most people are unable to find a comfortable position. This is due to the stone moving and brushing onto the very sensitive surface cell lining of the urinary system.

Other kidney stone symptoms may be related to infection: a burning sensation when passing urine; frequent urination; feeling like the bladder has not emptied completely; smelly or cloudy urine; and sometimes, urine discolouration when there is irritation caused by the movement of the kidney stone in the system.

People might even feel nausea or queasiness due to the intensity of the pain, and there may also be clear signs of infection, such as fever, chills and vomiting. Urgent medical attention should be sought if these severe symptoms occur.

Should kidney stones be a cause for concern?

People with unexplained intermittent niggling pains on the back should probably seek medical attention, because the pain could worsen and affect their quality of life. This should be either with a GP or directly with a urologist. They can carry out an assessment, arrange necessary scans and blood tests to see if there are stones (or any other cause), and determine the best treatment required.

Often, there are certain lifestyles and jobs that would dictate the urgency for kidney stone treatment. For example, pilots who must be medically approved kidney-stone free to be able to fly, or people who work with heavy machinery.

Do kidney stones require immediate medical treatment?

Some kidney stones require immediate medical treatment, especially:

• If a patient is experiencing severe pain which is not relieved by standard over-the-counter painkillers.
• If there are any concerns regarding blockage and if there are any signs of infection.

How are kidney stones removed?

Removal depends on the patient and the characteristics of the kidney stone, including:

• The size of the kidney stone
• The location of the kidney stone (for example, the kidney or the kidney draining tube, which is called the ureter)
• The symptoms the kidney stone is causing

Prevention is key once the kidney stone is treated. The NICE (National Institute for Health and Care Excellence) recommends to: drink 10 to 12 cups of fluid per day; make sure urine is a light-clear colour; and cut down salt and animal protein, which can all help to avoid kidney stone episodes. Certainly, if there are any high risk factors involved, such as a family history of kidney stones, more detailed evaluation and individualised treatment are needed.

In terms of treatment, there are medication treatments available for certain types of kidney stones, and in some patients that I have treated, medication alone has completely dissolved large kidney stones.

Another treatment option for kidney stones is shock wave lithotripsy, an outpatient-delivered treatment where ultrasound energy is focused through the skin to the kidney stone itself. This procedure is generally well tolerated.

Surgery is the next treatment offered for kidney stones, and there are different approaches.

One surgical option (called a ureteroscopy) is to pass small telescopes through the water pipe up through the kidney draining tube (the ureter) and into the kidneys. When the kidney stone is visualised directly through these telescopes, laser energy is then used to destroy the kidney stone.

Another surgical approach, typically for larger kidney stones, uses x-ray guidance to puncture directly through the skin into the kidney to remove the stone. This procedure is called a percutaneous nephrolithotomy.

Might kidney stones be a sign of bladder cancer or kidney disease?

Blood in the urine needs to be investigated on an urgent basis, because it could be a sign of kidney and/or bladder tumours.

In some cases, I have treated people presenting with kidney stones as well as bladder cancer. Here, treatment will typically focus on the cancer primarily.

Why might someone suffer from recurring kidney stones?

Some people have a strong family history of kidney stones, where every member of the family has had kidney stones. These people are clearly at a higher risk of having kidney stones.

There are a few rare genetic conditions, such as cystinuria, where people tend to have their first kidney stone episode in their teenage years and then require multiple treatments for recurrent kidney stones throughout their lifetime. These conditions are termed metabolic kidney stones.

Environmental factors, such as a hot climate and dehydration, also have a part to play in having increased kidney stone incidence. Also, men are more likely to have stones.

Despite these risk factors, an estimated 1 in 10 people will experience one kidney stone episode at some point in their lifetime.

If you are concerned about kidney stones, do not hesitate to seek expert diagnosis and treatment by visiting Mr Liew’s Top Doctors profile today.