This article explains how bladder stones are formed. It also covers symptoms, treatments, and ways to reduce the risk of bladder stones.
Here are some key points about bladder stones. More detail and supporting information is in the main article.
- Bladder stones are most common in men over the age of 50
- Underlying medical conditions are often responsible for bladder stones
- Symptoms of bladder stones include a change in urine color and pain when urinating
- Bladder stones are rarer in women
- Bladder stones can be a cause of blood in the urine
What are bladder stones?
Bladder stones can consist of a variety of minerals, accumulating in the bladder when urine is not fully removed during urination.
Bladder stones, also called vesical calculus, or cystoliths, are caused by a buildup of minerals. They can occur if the bladder is not completely emptied after urination.
Eventually, the leftover urine becomes concentrated and minerals within the liquid turn into crystals.
Sometimes, these stones will be passed while they are still very small. Other times, bladder stones can get stuck to the wall of the bladder or ureter (a pipe running from the kidney to the bladder).
If this happens, they gradually gather more mineral crystals, becoming larger over time.
Bladder stones can stay in the bladder for some time and do not always cause symptoms. They are often found when an X-ray is carried out for a different medical reason.
Bigger bladder stones may need to be removed by healthcare professionals.
Sometimes just one stone will develop, in other cases a group of stones might form. The stones vary in shape; some are almost spherical while others can be irregular shapes.
The smallest bladder stones are barely visible to the naked eye, but some can grow to an impressive size. The largest bladder stone, according to Guinness World Records, weighed almost 4 pounds 3 ounces and measured 17.9 x 12.7 x 9.5 centimeters.
Bladder stones may not produce symptoms straight away. But, if the stone irritates the bladder, symptoms can include the following:
- Discomfort or pain in the penis for males
- More regular urination or a stop-start flow
- Starting a stream during urination takes longer
- Pain in the lower stomach area
- Pain and discomfort when urinating
- Blood in the urine
- Cloudy or abnormally dark urine
Bladder stones start to grow when urine is left in the bladder after urinating. This is often due to an underlying medical condition that stops the bladder from completely emptying when using the toilet.
Conditions that stop the bladder from fully emptying include:
- Neurogenic bladder: If the nerves that run between the bladder and nervous system are damaged, for instance in a stroke or spinal injury, the bladder may not empty fully.
- Prostate enlargement: If the prostate is enlarged, it can press on the urethra and cause a disruption in flow, leaving some urine in the bladder.
- Medical devices: Bladder stones can be caused by catheters or other medical devices if they move to the bladder.
- Bladder inflammation: Infections of the urinary tract or radiation therapy can leave the bladder enlarged.
- Kidney stones: Kidney stones can migrate down the ureters and, if too large to pass, they will remain in the bladder and can cause obstruction. Kidney stones are more common than bladder stones.
- Bladder diverticula: Pouches can form within the bladder. If the pouches grow to a large size, they can hold urine and prevent the bladder from being fully emptied.
- Cystocele: In women, the bladder wall can become weak and drop down to the vagina; this can affect the flow of urine from the bladder.
Bladder stones develop most frequently in males over the age of 50.
Below are some of the factors that can increase the risk of bladder stones:
- Age and gender: Males develop bladder stones more often than females, especially as they get older.
- Paralysis: People with serious spinal injuries and loss of muscle control in the pelvic region are unable to empty their bladder completely.
- Bladder outlet obstruction: Any condition that blocks the flow of urine from the bladder to the outside world. There are a few different ways that the bladder can be blocked, the most common is an enlarged prostate.
- Bladder augmentation surgery: A type of surgery carried out to treat incontinence in women can lead to bladder stones.
Although some bladder stones do not produce any symptoms, they can still lead to complications if they are not removed. The two main complications are:
- Chronic bladder dysfunction: Frequent urination which is painful and uncomfortable. Sometimes, bladder stones can completely block urine from exiting the body.
- Urinary tract infections: repeated infections.
Tests and diagnosis
X-rays do not pick up all variations of bladder stone; other imaging methods may be required to make an accurate diagnosis.
Diagnosis of bladder stones can include a number of different tests:
- Physical exam: A doctor might put his hands on the lower abdomen to feel if the bladder is enlarged. They may examine the rectum to check if the prostate is enlarged.
- Urinalysis: A urine sample might be tested for signs of blood, bacteria, and crystallized minerals.
- Spiral computerized tomography (CT) scan: CT scans combine multiple X-ray images to build up a detailed image of internal organs.
- Ultrasound: Creates an image by bouncing sound off of internal organs.
- X-ray: Not all types of bladder stone show up on an X-ray.
- Intravenous pyelogram: A special fluid is injected into the veins and travels through to the kidneys and bladder. X-rays are taken throughout the procedure to look for signs of kidney stones.
If bladder stones are caught when they are still small, simply increasing the amount of water the individual drinks can be enough to pass them naturally.
If they are too large to pass in the urine, treatment for bladder stones normally involves either breaking them up or removing them by surgery.
Breaking up bladder stones
In a procedure called cystolitholapaxy a doctor inserts a thin tube with a camera on the end into the urethra (the opening found at the end of the penis or above the vagina). The doctor can view the stones through the tube and break them down.
Complications from cystolitholapaxy are rare but can include tears in the bladder wall, and infections.
If the stones are too large to be broken down using cystolitholapaxy, surgery is an alternative treatment option. The surgeon will enter the bladder through a cut in the abdomen and remove the bladder stones. Any surgical procedure comes with some risks, so cystolitholapaxy is always the first choice.
Because bladder stones are caused by a range of medical illnesses, there are no specific ways to prevent them. However, if an individual experiences any odd urinary symptoms - pain, discoloration, blood - getting a medical opinion earlier rather than later is advisable. Drinking plenty of fluids will also help break down any developing stones.
Some people with urinary tract infections feel that there is urine left in the bladder after urinating. In these cases, it is best to try urinating again 10-20 seconds after the first attempt. This is called "double voiding" and can help prevent stones from forming.
Some research indicates that if you already have an enlarged prostate, sitting down to urinate can help make sure that the bladder is emptied fully. This, in turn, prevents or slows the buildup of bladder stones.