Bladder stones are crystal masses made from the minerals and proteins found in urine. Stones can form anywhere in the urinary system, but end up in the bladder. The most common types contain calcium salts. They begin as tiny grains, but can grow to an inch or larger in diameter. Sometimes, multiple small stones form, and there may be up to a hundred of these in one person’s bladder.
People with bladder stones sometimes have no symptoms. More often, however, they will have difficulty in passing urine from their bladder, as the stone or stones tend to lodge in the narrow area between the bladder and the external urine passage (the urethra). Stones can block the flow of urine completely, causing painful overfilling of the bladder, or they can cause intermittent obstruction of the flow, with a stuttering stream of urine. They may cause minor or severe pain. They may lead to an infection or bleeding. The urine may be obviously red and have blood clots or there may be just trace amounts of blood that only a chemical test or microscope can detect.
The causes of bladder stones are not completely understood. Diet and fluid intake appear to be important factors. Stones seem to be more common in hot climates and during summer months. Bladder stones are much more common in some Asian countries, especially India, than in the U.S. They are more common in the southeast and southwest regions of the U.S. than in other areas. This may be because hot weather leads to body fluid loss. It may also be due to regional diet. There is also a strong association with poverty. Stones are more common in men and rare in children and African-Americans.
Most bladder stones are made of calcium oxalate. These are more often single than multiple stones. They may be caused by excessive levels of calcium or oxalate in the blood and urine because of hormone or kidney function problems. Frequently, in older men and women, they are associated with poor emptying of the bladder when urinating, due to prostate overgrowth in men, or poor bladder pressure in women.
Some bladder stones are made of uric acid, and may be associated with gout. Uric acid stones are particularly common in Asia. Uric acid stones tend to be multiple and not usually very large.
Another type of stone is called a triple phosphate stone because of the presence of magnesium and ammonia and phosphate. This type of stone is usually associated with chronic infection in the bladder and may grow very large.
Bladder stones are most often diagnosed following investigations that are done because of the symptoms caused by the stone(s). The first test typically done is a urinalysis, where a urine sample is analyzed with chemicals and also a microscope. Blood cells can be seen easily, and if present, a cystoscopy is done. Cystoscopy involves looking in the bladder with a scope and viewing the interior. Stones can easily be seen. Most stones contain calcium and will show up on a plain x-ray of the abdomen. Uric acid stones will not be seen on plain x-ray.
The treatment of bladder stones is typically surgical removal, which is done through an incision in the lower abdomen if the stone is very large. For smaller stones, a scope can be passed through the urethra (urine channel), and the stones can be broken up with laser or ultrasound, and the pieces washed out with normal urination. If the stone is thought to be due to enlarged prostate or some other bladder anatomical abnormality, then that abnormality may need to be treated surgically as well, to prevent more stones. Treatment of urinary infection with antibiotics is also necessary.
It is important to drink plenty of fluids to flush out the urinary system. The more dilute the urine is, the less likely bladder stones will form. (This is also true for kidney stones.)
The symptoms of bladder stones can be alarming. They are also very similar to the symptoms of some more serious illnesses such as bladder or kidney cancer. If you notice blood in your urine, consult your healthcare provider quickly, even if you have no pain. Although the blood may sometimes clear up very quickly, do not be reassured by this. Seeing blood in the urine even one time is a very important warning signal of possible major illness, and needs to be checked immediately and carefully.
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