A bladder infection is an infection that causes inflammation of the bladder wall. In most cases it is an acute bladder infection, which is caused by bacteria in the bladder. In case of a chronic (interstitial) bladder infection, no bacteria are present, but the bladder is constantly inflamed by a damage of the mucosa.


A bacterial bladder infection usually occurs when bacteria enter through the urethra and begin to multiply. This can occur in women as a result of sexual intercourse. During sexual activity, bacteria are introduced via the urethra into the bladder. But sexual inactive girls and women are also susceptible to infections of the urinary tract, because the female genital area often houses bacteria that can lead to a bladder infection.
Most cases of bladder infection are caused by the bacterium Escherichia coli, a species that is very frequently found in the genital area. Although bacterial infections are the most common cause of bladder infection, other factors can also lead to this condition. A bladder infection is not contagious.


The following signs and symptoms may occur in a bladder infection:

Bedwetting in young children can also be a sign of bladder infection. When they are treated quickly and correctly, bladder infections rarely cause complications. But without treatment they can cause complications, such as kidney infection and blood in the urine.


When bladder infection is suspected, the doctor may order for a urinalysis to determine the composition of the urine. There is primarily sought for bacteria, red blood cells, proteins and pus in the urine.
Another examination is cystoscopy. This is an inspection of the bladder with a thin tube with a camera (cystoscope) which can be inserted through the urethra into the bladder. This way, the doctor can also take a tissue biopsy for examination in the laboratory.
Imaging techniques, such as X-ray or ultrasound, are only needed when no evidence of infection was found. They may confirm or exclude other possible causes of a bladder infection, such as a tumor or structural defects in the bladder.


An acute bladder infection, caused by a bacterial infection, is in first instance treated with antibiotics. What medicines are used and for how long, depends on the overall health of the patient and the bacteria found in the urine. The symptoms usually disappear within a few days after start of the treatment. In case of recurring infections, prolonged antibiotic treatments may be needed.
In case of a chronic bladder infection, the cause of the inflammation is uncertain. No single treatment works best for all cases. Commonly used treatments include interventions to the bladder, such as bladder distension (injecting water in the bladder so that it expands), surgery, nerve stimulation and medicines that are taken by mouth or injected directly into the bladder.


Simple bladder infections usually heal without any problems with antibiotics. In some cases, an untreated bladder infection can rise up to the kidneys, causing a kidney infection. In case of a complicated bladder infection, prospects depend on the clinical situation. Patients can get seriously ill if the infection spreads through the urinary tract to the blood.