Pain in the region of the bladder usually results from a urinary tract infection, or UTI. Urinalysis is the standard method for positively confirming a UTI, but a single negative urinalysis does not necessarily rule out infection, says "Harrison’s Principles of Internal Medicine." If the pain persists after multiple negative urine cultures and there are no other signs of infection, such as fever, doctors will begin to consider other, noninfectious causes for the pain.
Stones are the most common cause of bladder pain next to infection. Stones are formed when various substances dissolved in the urine precipitate out to form crystals. All crystals actually begin in the kidneys, but some remain small until they move into the bladder, at which point they begin to grow, according to "Harrison’s Principles of Internal Medicine."
Stones in the bladder itself usually do not cause symptoms unless they are large or numerous enough to injure or inflame the bladder wall. Pain and bleeding most often occur when stones pass from the kidneys to the bladder through the ureters or out of the bladder through the urethra. The treatments for bladder stones depend on the substance that comprises the stone. Some can be treated with medication or diet, while others require surgery.
Urinary Tract Obstruction
Urinary tract obstructions are the next most common cause of bladder pain. Obstructions of the bladder outlet or the urethra can lead to pain from the constant distension or over-distension of the bladder caused by chronic retention of urine, says "Harrison’s Principles of Internal Medicine."
The pain from urinary tract obstruction is usually accompanied by a constant feeling of bladder fullness. The most common causes of bladder obstruction in older men are benign enlargement of the prostate and prostate cancer. Often, urinary retention is the first symptom of prostate problems that patients notice. In children, the most common causes of obstruction are congenital defects in the urinary system that make obstruction more likely. These defects usually become apparent in the first year or two of life.
Bladder cancer is another possible source of non-infectious pain. It is the disease that worries patients the most, but fortunately, it is less common than the other causes of bladder pain mentioned thus far. The first noticeable symptom of bladder cancer is blood in the urine, with pain or other sensations of discomfort following soon afterward, reports "Harrison’s Principles of Internal Medicine."
The biggest risk factor for bladder cancer is cigarette smoking, with radiation and exposure to certain parasites and industrial chemicals, such as dyes, also implicated. Bladder cancer is usually treated with surgery and sometimes with chemotherapy if it has spread to other parts of the body.