The most common cause of bladder stones is an inability to completely empty your bladder of urine.

Urine is produced by your kidneys. It is made up of water mixed with waste products that the kidneys remove from your blood. One of the waste products is urea, which is made up of nitrogen and carbon.

If any urine remains in your bladder, the chemicals in urea will stick together and form crystals. Over time, these crystals will harden and form bladder stones.

Some common reasons why people are unable to empty their bladder fully are described below.

Prostate enlargement

The prostate is a small gland only found in men. It is located in the pelvis between the penis and the bladder, and surrounds the tube that carries urine from the bladder to the end of the penis and out of the body (the urethra).

The main function of the prostate is to help the production of semen. In many men, the prostate becomes enlarged as they grow older.

In around one third of men over the age of 50 the prostate gland puts pressure on the urethra and interrupts the normal flow of urine from the bladder.

If treatment for enlarged prostate is given it’s unusual for men to develop bladder stones. However, in a minority of men who fail to respond to treatment, there is an increased risk of developing bladder stones.

Read more about prostate enlargement.

Neurogenic bladder

Neurogenic bladder is a condition where nerves that control the bladder are damaged, which means preventing that a person from emptying their bladder fully.

Neurogenic bladder can be the result of:

• serious injury to your spinal column (a long band of nerves that runs from the brain down the centre of the spine) resulting in some degree of paralysis
• conditions that cause damage to the nervous system such as motor neurone disease or spina bifida

Most people with a neurogenic bladder require a catheter to empty their bladder. A catheter is a tube inserted into the urethra and moved up into the bladder. The urine is drained out of the bladder through the catheter. This is known as urinary catheterisation.

However, a catheter, while reasonably effective, is not a perfect substitute for normal bladder control and often leaves a small amount of urine in the bladder. This can lead to the formation of bladder stones.

It is estimated around 1 in 10 people with a neurogenic bladder will develop bladder stones at some point in their life.

Cystocele

A cystocele is a condition that affects women and develops when the wall of the bladder becomes weakened and begins to drop down on to the vagina. This can affect the normal flow of urine out of the bladder.

A cystocele can develop during a period of excessive straining, such as childbirth, chronic constipation or heavy lifting.

Bladder diverticula

Bladder diverticula are pouches that develop in the wall of the bladder. If the diverticula grow to a certain size, it can become difficult for a person to empty their bladder fully.

Bladder diverticula can be present at birth or develop as a complication of infection or prostate enlargement.

Bladder augmentation surgery

There is a type of surgery known as bladder augmentation surgery where a piece of the bowel is removed and attached to the bladder to make it larger.

This can be useful in treating a type of urinary incontinence known as urge incontinence.

Research suggests that around 1 in 20 people who undergo this type of surgery will develop bladder stones.

Diet

Poor diet is a much less common cause of bladder stones in England, but is relatively common in parts of the developing world.

A diet high in fat, sugar or salt but low in vitamin A and vitamin B can increase the risk of bladder stones, especially if a person is also not getting enough fluids to drink (dehydration).

All three of these factors can alter the chemical make up of urine, making the formation of bladder stones more likely.

If your GP suspects that you have a bladder stone, they will refer you to hospital for testing.

It is likely that you will first be given blood and urine tests. A blood test will detect if there is an infection inside the bladder.

Imaging tests

The next stage is to take an X-ray of your bladder. Not all types of bladder stones will show up clearly on X-rays, so a negative X-ray result does not always mean you do not have bladder stones.

An ultrasound scan may be used instead of an X-ray.

Cystoscopy

Abnormalities in the bladder can also be identified using a cystoscopy.

In this procedure, a thin, hollow viewing tube called a cystoscope is inserted into your urethra (the opening in the penis or vagina through which you urinate) to view the inside of your bladder.

Bladder stones are stones that form inside the bladder, which can vary in size.

The stones can irritate the wall of the bladder, disrupt the flow of urine out of the bladder and cause infections.

This can cause symptoms such as:

• pain, which can often be severe, in the lower abdomen
• changes to the normal pattern of urination, such as having to pass urine more frequently or waking up in the night needing to go to the toilet
• blood in your urine 
• pain when urinating

Read more about the symptoms of bladder stones.

When to see your GP

It is recommended that you contact your GP if you experience any of the symptoms mentioned above. They are not necessarily the result of bladder stones but they will require further investigation.

Why bladder stones happen

The most common cause of bladder stones is when a person is unable to completely empty the urine from their bladder.

If urine sits in the bladder for a long time, chemicals in the urine form crystals which come together and harden to form bladder stones.

Reasons why a person may be unable to empty their bladder completely include:

• in men, having an enlarged prostate gland that blocks the flow of urine out of the bladder
• an injury to the spine that damages the nerves used to control the bladder, particularly in people with catheters

Read more about the causes of bladder stones.

A poor diet can also contribute to the formation of bladder stones. A diet lacking in nutrients and fluids can change the chemical make-up of urine, making the formation of stones more likely.

A low-fat, high-fibre diet is recommended, including plenty of fresh fruit and vegetables (at least five portions a day) and wholegrains.

Read more about healthy eating.

Treatment

Surgery is usually required to remove the stones from the bladder. The most common procedure is known as a cystolitholapaxy, where a telescope and stone-crushing devices are used to break up the stones before they are removed.

It is also important to treat the underlying causes of bladder stones (where possible) to prevent new stones developing in the future.

Read more about treating bladder stones.

Who is affected?

Each year in England an estimated 6,000 people go into hospital to be treated for bladder stones.

Most cases of bladder stones affect older men aged 50 or above, because of the link with prostate enlargement.

Bladder stones can affect children, but this is much less common, with an average of 20 to 40 cases a year.

In some cases, bladder stones do not cause any symptoms. This is because they can be small enough to be passed out of the bladder when a person urinates.

However, most people with bladder stones do experience symptoms because the stones either irritate the wall of the bladder or block the normal flow of urine from the bladder.

Other symptoms of bladder stones include:

• in men, pain in the penis, scrotum and lower abdomen
• pain or difficulty when urinating
• cloudy or darkly-coloured urine
• blood in your urine 

Additional symptoms in children include:

• in boys, a persistent and often painful erection, that is unrelated to sexual desire (the medical term for this is priapism)
• bedwetting

When to seek medical advice

It is strongly recommended you contact your GP if you experience any of the following symptoms:

• persistent abdominal pain
• a change in your normal pattern of urination
• blood in your urine

These symptoms are not necessarily the result of bladder stones but will require further investigation.

It may be possible to flush small bladder stones out of your bladder by drinking lots of water (try around 1.2 litres or 6-8 glasses a day).

However, as most people with bladder stones have problems completely emptying urine from their bladder, it is unlikely that the stones will pass out using this method.

Types of surgery

The main types of surgery used to treat bladder stones include:

• a transurethal cysolitholapaxy – the most common procedure used to treat adults with bladder stones
• a percutaneous suprapubic cystolitholapaxy – mainly used to treat children to avoid damaging their urethra but sometimes used for adults with very large bladder stones
• an open cystotomy – often used in men where the prostate has grown so large that it obstructs other procedures, or if the stone is very large

These are explained in more detail below.

Transurethral cystolitholapaxy

During the procedure the surgeon will insert a small, rigid tube that contains a camera at the end (a cystoscope) into your urethra and up into your bladder.

The camera is then used to locate any stones. A ‘crushing’ device can be used, or lasers or ultrasound waves transmitted from the cystoscope to break up the stones into smaller fragments, which can be washed out of your bladder with fluids.

A transurethral cystolitholapaxy is carried out under regional or general anaesthetic, so you should not feel any pain.

During the cystolitholapaxy procedure, there is a risk that you will develop an infection, so you may be given antibiotics as a precaution. There is also a small risk of injury to the bladder.

Percutaneous suprapubic cystolitholapaxy

During the procedure the surgeon makes a small incision in the skin, in the lower abdomen. A further incision is made in the bladder and the stones are removed.

A percutaneous suprapubic cystolitholapaxy is carried out under general anaesthetic.

Open cystostomy

Open cystostomy is similar to a percutaneous suprapubic cystolitholapaxy except the surgeon makes a much larger incision in the abdomen and bladder.

Alternatively, an open cystostomy may be combined with other types of surgery, such as removing some or all of the prostate or bladder diverticula (pouches that develop in the lining of the bladder).

An open cystostomy is carried out under general anaesthetic.

The disadvantage of an open cystostomy is that it causes more post-operative pain and has a longer recovery time, but this procedure is required if the stone is large.

A urethral catheter is also required for a day or two after the surgery.

Complications of surgery

The most common complication of bladder stone surgery is an infection of the bladder or urethra. These are collectively known as urinary tract infections or UTIs.

UTIs affect around 1 in 10 people who have undergone bladder surgery and they can normally be treated with antibiotics.

Recovery and follow-up

If you have transurethral cystolitholapaxy or percutaneous suprapubic cystolitholapaxy you will normally need to stay in hospital for a few days to recover.

In open cystostomy it may take several days before you are well enough to go home.

You will probably be asked to attend a follow-up appointment where X-rays or a CT scan can be used to check that all the fragments of the bladder stones have been removed from your bladder.

Treating the underlying cause

Once the bladder stones have been removed it is necessary to treat the underlying cause to avoid new bladder stones forming.

Prostate enlargement

Prostate enlargement can be treated using medication that can both help reduce the size of the prostate and relax the bladder, making it easier to pass urine.

If medication fails to work then surgery may be required to remove some or all of the prostate.

Read more about the treatment of prostate enlargement.

Neurogenic bladder

If you have a neurogenic bladder (inability to control the bladder due to nerve damage) and you develop bladder stones it is often a sign that you need to change the way in which you are draining your bladder.

You may need further training in fitting your catheter or you may need to change the type of catheter you are using and use medication to help control the bladder.

Read more about urinary catheterisation.

Cystocele

Mild to moderate cases of cystocele (where the walls of the bladder weaken and begin to drop down into the vagina) can be treated using a device called a pessary.

A pessary is designed to fit inside the vagina and hold the bladder in its correct location.

More severe cases may require surgery to strengthen and support the walls of the bladder.

Bladder diverticula

Bladder diverticula (pouches that develop in the wall of the bladder) may require surgery to remove any pouches.