Can kidney stones cause UTI: how they are related to each other?

Are you suffering from kidney stone disease? Do you frequently suffer from urinary tract infections? And are you worried that your UTI is related to the stone in the kidney? You are on the right page to get the answers to these questions.

In this article, we are going to discuss the relationship of kidney stones to UTI, the symptoms of those conditions, and a brief about the management. Let’s start.

Does kidney stone cause urinary tract infection?

The relationship between kidney stones and UTI is well documented. Some types of urinary tract infections are responsible for stone formation. But all stones are not the result of infection. We will discuss that later. In this section, we are going to discuss if a stone can cause UTI.

Urinary stones are usually formed within the kidneys. Initially, minute (extremely small) stones are formed which increases in size gradually. Those may stay within the kidney for long times or travel downwards via the ureter to the urinary bladder. A small stone may pass with urine. But if you are unlucky, it may stay and enlarge within the urinary bladder producing bladder stone.

The stone may create complete or partial blockage in any part of the kidney or urinary tract. Obstruction to urine flow creates a favorable environment for the bacteria to grow and multiply.

When located within the kidney, it increases the risk of pyelonephritis. If it obstructs the ureter, it may cause hydronephrosis (swelling of the kidney) which increases the risk of kidney infection.  When located in the bladder it may cause cystitis. Thus kidney stone increases the risk of UTI.

The stone may persist for a long time. And it may be multiple which often travels through the urinary system if small in size. Moreover, a person who develops renal stone once is prone to develop recurrent stone. All of these situations lead to recurrent UTI.

Recent microbiological studies with kidney stones show that the presence of bacterial isolates is common in stones. Even many bacteria which do not cause stone formation (e.g. Escherichia coli), were found in the stone. This supports that, the kidney stone itself facilitates infection.

Can symptoms of kidney stone mimic UTI’s?

A stone in the kidney may remain asymptomatic for a long duration. You may never know that you have a stone unless identified in a scan done due to other problems. But sometimes it produces symptoms that may be mild or severe.

The most common symptoms are pain in the back or loin, the passage of blood with urine, cloudy or smelly urine,  nausea, vomiting, etc. 

There are some differences, but it may confuse you with UTI. Especially if the stone remains in the bladder or lower part of the ureter. A stone may irritate the bladder wall leading to lower abdominal pain and frequency of urination.

These are very common presentations in cystitis (lower UTI). Moreover, if the stone gets infected it will produce fever which may mimic UTI. So, we can say that stone may produce UTI-like symptoms even if there is no infection.

When to think I am suffering from stone, not UTI?

Well, this is a clinical question and you may not be able to differentiate stone from UTI. Your doctor will analyze your signs and symptoms and try to identify the cause. However, we will discuss some important points in simplified terms. It will help you to understand the differences.

First of all, the dull aching pain of kidney stones is felt usually at one side of the body, over the lower back. During the passage of stone through the ureter, you will suffer severe colicky pain over the loin and groin.

Doctors often describe it as loin-to-groin pain. The pain is not felt every day. Rather it comes and goes in episodes.  But the pain in UTI is usually felt in the lower abdomen, acute in nature, and continues unless the infection resolves. It is not so severe as colicky pain.

Secondly, the stone is usually not associated with fever unless infected. But the urinary tract infection is usually associated with fever, especially when it involves the kidney (pyelonephritis) or is left untreated.

Thirdly, urinary frequency and urgency are very common in UTI. But in the case of stone, it can be found only when the stone is located within the urinary bladder.

And fourthly, the symptoms of UTI improve with antibiotics. But the kidney stone can’t be treated with antibiotics.

Please note that all of these points are described based on the common presentation of both diseases. But, the presentation of an illness is not always similar in all patients. Depending on the types, severity, age, sex, general condition, and body immunity, the same disease may present in different ways.

Even physicians can’t always differentiate those without investigation. So, talk to your doctor. He will help you to get diagnosed.

Between kidney stones and UTI, which one should be treated first?

Sometimes, you may suffer from both stone and UTI. Due to their close relationship, we often get UTI patients visiting with kidney stones A stone may lead to recurrent UTI and vice versa. Especially if you are a man and you suffer from recurrent UTI-like symptoms, stones should be suspected.

Whatever the sequence is, you should always get treated for the infection first.

A urinary tract infection is an acute condition. If not treated, it may turn into a complicated UTI very soon. The infection may even spread to blood leading to septicemia. It is a life-threatening condition.

On the other hand, stones disease is a chronic condition. It develops slowly and requires time to cause complications. Moreover, the stone disease can’t be treated abruptly. Small stones in favorable locations may be excreted spontaneously with urine. And large stones may require invasive( e.g. surgery) or non-invasive (e.g. shockwave lithotripsy) interventions.

In every case, prior management of the infection is a must. Without managing the infection, going for any intervention is risky. So, your doctor will treat your UTI first with an antibiotic. Then he will go for the suitable intervention as needed.

Do UTI bacteria lead to stone formation?

Recurrent urinary tract infection is an established risk factor of urinary stone formation. In a whole population survey of Taiwan, a UTI history was the most common associated condition in children with newly diagnosed urinary stones.

Overall, 34% of children, 44% of females, and 24% of males diagnosed with kidney stones had a history of UTI. Urinary tract infection is caused by a wide range of organisms. Among those, some are notorious for their relationship with kidney stones. Surprisingly, the most common uropathogenic organism Escherichia coli does not contribute to kidney stone disease.

The most common bacteria that cause stone formation is the Proteus species. Other bacteria include Ureaplasma urealyticum, Staphylococcus species, Klebsiella species, Providencia species, and Pseudomonas species.

These bacteria can produce a special enzyme called urease. This enzyme causes the breakdown of urinary urea into ammonia and hydroxyl ions. The increased amount of ammonia in the urine produces a suitable environment for stone formation.

This type of stone is called struvite stone or infection stone. Struvite stones are dangerous compared to other types of stone. They grow rapidly and often take the shape of staghorn. So, they are also called staghorn calculi.

Complete removal is mandatory in case of an infection stone. The most important point is, any small remaining part may serve as a nidus (a focus or point of origin) for future stone formation. So, the recurrence rate is high.

How to facilitate the passing of kidney stones with urine?

First of all, you have to understand that not all kidney stones will pass with urine. It depends on the size, shape, and location of the stone. If you have a small stone of less than 0.5cm, you can expect to pass it spontaneously with urine. A bit larger ones, up to 2cm are difficult to pass. But it can be broken into smaller pieces with the administration of an external shockwave therapy targeted at the stone.

The process is called extracorporeal shockwave lithotripsy(ESWL). It is a very popular method to treat stones effectively without surgery. But, larger stones that are more than 2cm usually require surgical removal. However, if the stone is located in the lower pole of the kidney, and not within the collecting systems ( the ducts for urine excretion from the kidney), even smaller stones may require surgery.

In the case of small stones, you will usually develop symptoms when it has already started traveling through the ureter. During the passage of stone through the ureter, you may feel colicky pain.

Stone less than 0.4cm may pass without pain or mild pain. But larger stones may cause severe pain and require painkiller medication to get relief. Your doctor may prescribe analgesic drugs like ketorolac, diclofenac, or even tramadol. Most often, injectable formulations are required for quick results.

To facilitate the passage of stone, you should take enough water to produce two liters of urine output per day. Do regular exercise like walking, jumping, etc. It will help you a bit. Some high oxalate and urate-containing food may contribute to enlarge the stone.

Avoid such food as spinach, beets, almonds, red meat, seafood, etc to prevent the growth of the stone. Citrus fruits like lemon, orange, etc prevent stone formation and even help to reduce the size. Take a glass of lemon juice or lemon water every day. It will help you a lot to pass the stone.

Some drugs may help to pass the stone. Some urine alkalinizing agents prevent further enlargement of the stones. And some medicines help to evacuate the stones from the ureter. Talk to your doctor. He will assess your suitability and advise accordingly.

So, that’s all for now. Hope you have got some idea about the relationship between UTI and kidney stones. But, don’t take any decision regarding the treatment without asking your doctor. You can also get back to us to clear your confusion if any. Thanks for reading the article.

Ph. Abbas

A pharmacist who decided to write detailed articles about urinary tract infections (UTI).

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