Bladder stones

Definition

Bladder stones are small masses of minerals that form in your bladder, the balloon-shaped organ in your pelvis that stores urine. Bladder stones, also called bladder calculi, often form when concentrated urine sits in your bladder. As urine stagnates, minerals in the urine form various crystals that may combine to form "stones." Bladder stones usually develop secondary to another condition, such as an enlarged prostate or a urinary tract infection.

The incidence of bladder stones in the United States and western Europe has been declining over the past century due to improvements in nutrition and infection control. In these geographic areas, middle-aged and elderly men are at highest risk of developing bladder stones. However, bladder stones remain a common problem in developing countries, especially among children.

Lower abdominal pain and painful urination are common symptoms of bladder stones. Bladder stones are usually removed by your doctor, but small stones may pass on their own. Left untreated, bladder stones can cause infections and other complications.

Symptoms

Some people with bladder stones don't have any signs and symptoms. But if a bladder stone irritates the bladder wall or blocks the flow of urine from your bladder, you may experience signs and symptoms. Bladder stone symptoms may include:

• Lower abdominal pain
• In men, pain or discomfort in the penis
• Painful urination
• Frequent urination, especially during the night
• Difficulty urinating or interruption of urine flow
• Urine leakage (incontinence)
• Blood in your urine
• Abnormally dark-colored urine

Causes

Urine is liquid waste filtered from your blood by a pair of organs called the kidneys. Urine passes out of your kidneys through two slender tubes (ureters) and enters your bladder, a hollow, balloon-shaped organ, where it is stored. When you go to the toilet, urine flows out of your bladder, down another tube called the urethra and out your body.

Bladder stones often occur when urine stagnates in your bladder. Usually, there's an underlying condition affecting your bladder's ability to empty itself completely. These conditions may include:

• Benign prostatic hyperplasia (BPH). An enlarged prostate is one of the most common causes of bladder stones in men. If your prostate becomes enlarged, it can compress the urethra and interrupt urine flow, causing urine to stagnate in your bladder.
• Neurogenic bladder. Normally, nerves carry messages from your bladder to your brain and then back from your brain to your bladder muscles, directing the bladder muscles to tighten or release. If these nerves are damaged, your bladder may become underactive — meaning that your bladder doesn't empty completely.
• Bladder diverticula. Bladder diverticula are weakened areas in the bladder wall that bulge outward in pouches. Bladder diverticula may be present at birth or develop later as a result of benign prostatic hyperplasia or other conditions that cause poor bladder drainage. Urine may stagnate in the diverticula and stones can develop.

Other conditions that can cause bladder stones include:

• Inflammation. Bladder stones can develop if your bladder becomes inflamed. Urinary tract infections, which are infections caused by bacteria or other infectious agents in your urinary tract, and radiation therapy to your pelvic area can both cause bladder inflammation.
• Medical devices. Occasionally, catheters — slender tubes inserted through the urethra into your bladder to help urine drain out of your bladder — and other foreign objects placed in your bladder can cause bladder stones. This is because mineral crystals, which can later become stones, tend to form on the surface of these devices.

Bladder stones aren't the same as kidney stones, which are masses of crystallized minerals that form in your kidneys. However, small kidney stones occasionally travel down the ureters into the bladder, where they can continue growing into larger stones.

What bladder stones look like
Bladder stones form in a diverse array of shapes and sizes. Bladder stones may be:

• Single or multiple
• Tiny or large enough to fill your entire bladder
• Soft or hard
• Smooth and round or jagged and spiked like toy jacks

Your urinary system, which includes your kidneys, ureters, bladder and urethra, is responsible for removing waste from your body through urine.

Your bladder stores urine produced by your kidneys and expels it through a tube called the urethra.

Risk factors

Bladder stones most commonly affect people living in developing and less developed areas, including Thailand, Burma, Indonesia, the Middle East and North Africa.

In the Western hemisphere, where bladder stones occur far less often, men older than the age of 50 are most likely to develop bladder stones.

When to seek medical advice

If you notice any signs or symptoms of bladder stones, such as lower abdominal pain, painful or frequent urination, difficulty urinating or blood in your urine, contact your doctor. Bladder stones often signal the presence of an underlying disorder, so it's important to get checked out.

Tests and diagnosis

Making a diagnosis of bladder stones begins with a physical exam: Your doctor will likely feel your lower abdomen to see if your bladder is distended and, if applicable, perform a rectal exam to determine whether your prostate is enlarged. You may also discuss any urinary signs or symptoms that you've been having.

Other tests used to make a diagnosis of bladder stones may include:

• Urinalysis. A sample of your urine may be collected and examined for microscopic amounts of blood, bacteria and crystallized minerals. A urinalysis is also helpful for determining whether you have a urinary tract infection, which can cause bladder stones.
• Cystoscopy. During cystoscopy, your doctor inserts a tube with a small camera at the end (cystoscope) through your urethra and into your bladder. After the cystoscope is in place, your doctor fills the cystoscope with water, which flows into your bladder. As fluid fills your bladder, it stretches the bladder wall, allowing your doctor to view the bladder interior. Cystoscopy is a useful test for diagnosing bladder stones because it helps your doctor see the number, size and location of the stones in your bladder.
• X-ray. An X-ray of your kidneys, ureters and bladder helps your doctor determine whether stones are present in your urinary system. This is an inexpensive and easy test to obtain, but some types of stones aren't visible on X-ray pictures.
• Intravenous pyelogram. An intravenous pyelogram is a test that uses dye to visualize organs in your urinary tract. Dye injected into a vein in your arm flows into your kidneys, ureters and bladder, outlining each of these organs. X-ray pictures are taken at specific time points during the procedure to check for stones.
• Ultrasound. An ultrasound, which bounces sound waves off organs and structures in your body to create pictures, can help your doctor visualize bladder stones.
• Computerized tomography (CT) scan. A CT scan is a highly sensitive and specific tool for detecting bladder stones of all types along your urinary tract.

Complications

Bladder stones that aren't removed can cause complications. These may include:

• Chronic bladder dysfunction. Left untreated, bladder stones can cause long-term urinary problems, such as pain or frequent urination. Bladder stones can also lodge in the opening where urine exits the bladder into the urethra, and block the passage of urine out of your body.
• Urinary tract infections. Recurring bacterial infections in your urinary tract may be caused by bladder stones.
• Bladder cancer. Chemicals or objects that cause chronic irritation of the bladder wall, including bladder stones, increase your risk of developing bladder cancer.

Treatments and drugs

Bladder stones usually need to be removed. If the stone is small, your doctor may recommend that you drink an increased amount of water each day to help the stone pass. If the stone is large or doesn't pass on its own, your doctor may need to remove the stone.

Bladder stones are usually removed during a procedure called a cystolitholapaxy. During this procedure, your doctor inserts a small tube with a camera at the end (cystoscope) through your urethra and into your bladder to view the stone. Your doctor uses a laser, ultrasound or mechanical device to break the stone into small pieces and then flushes the pieces from your bladder.

You'll likely have regional or general anesthesia prior to the procedure to make you comfortable. Complications from a cystolitholapaxy aren't common, but urinary tract infections, fever, a tear in your bladder and bleeding can occur. Your doctor may give you antibiotics before the procedure to reduce the risk of infections. About a month after the cystolitholapaxy, your doctor will likely check to make sure that no stone fragments remain in your bladder.

Occasionally, bladder stones that are large or too hard to fragment are removed through open surgery. In these cases, your doctor makes an incision in your bladder and directly removes the stones. Any underlying condition causing the stones, such as an enlarged prostate, may be corrected at the same time the stones are removed.

Prevention

Bladder stones usually result from an underlying condition that's hard to prevent. However, you can decrease your chance of developing bladder stones by following these tips:

• Ask about unusual urinary symptoms. Early diagnosis and treatment of an enlarged prostate or another urological condition may reduce your risk of developing bladder stones.
• Drink plenty of fluids every day. Drinking large quantities of fluids, especially water, may help prevent bladder stones because fluids dilute the concentration of minerals in your bladder. How much fluid you should drink depends on your age, size, health and level of activity. Ask your doctor what's an appropriate amount of fluid for you.
• Consider cranberry juice. This type of juice contains a substance that slows bacterial growth. Drinking cranberry juice may help prevent urinary tract infections, which can lead to bladder stones.