The bladder is a hollow muscular organ situated in the pelvic cavity. It is connected to the kidney via two tubes called the ureters. Expulsion of urine from the urinary bladder is called micturition, urination or voiding. The average capacity of the bladder is 700-800ml. When the amount of urine in the urinary bladder exceeds 200-400ml, special cells that act as stretch receptors in the wall of the bladder transmit sensory impulses to the spinal cord and to the brain, which initiates a conscious desire to expel urine, and thus triggers a reflex called the micturition reflex. This reflex causes holding the bladder closed to relax, resulting in urination.
Increased frequency refers to a need to urinate more often than usual. Increased urgency refers to a sudden, compelling urge to urinate, accompanied by discomfort in the bladder. Urinary frequency is often accompanied by an increase in the total daily amount of urine. It may be a sign of reduced bladder capacity, which might be caused by infections or masses. Painful urination is known as dysuria, and may be experienced as a burning or stinging sensation.
Dysuria may suggest irritation or swelling in the bladder, which may be caused by an infection.
There are many causes of urinary frequency. Anything that increases urine production, such as fluid tablets or raised blood sugar levels, can cause frequency. A frequent need to urinate without an increase in the amount of urine suggests an irritative cause such as a urinary tract infection (UTI) or tumour. A mass or tumour compressing the outside of the bladder can also cause urinary frequency because the mass reduces the effective capacity of the bladder. An inability to fully empty the bladder because of partial obstruction, often from an enlarged prostate, can produce frequency.
- Excessive fluid intake.
- Urinary tract infection.
- Diabetes mellitus.
- Diabetes insipidus (a rare condition).
- Inflammation or enlargement of the prostate.
- Bladder infection.
- Medications such as diuretics.
- Urinary tract infection.
- Cancers of the bladder and prostate.
- Sexually transmitted infections such as chlamydia and gonorrhoea.
- Stones in the bladder (which are usually produced in the kidney).
- Analysis of urine
- Culture of urine
- Cystometry (a measure of pressure inside the bladder)
- Neurological tests
- Ultrasonography such as a pelvic or abdominal ultrasound
Treatment of urinary frequency and /or dysuria depends the identified cause. For instance, if certain medications are causing these symptoms, they may need to be changed. Infections of the urinary tract are treated with the antibiotics. If a mass suspected of being a cancer is found anywhere in the urinary tract, referral to a urologist (urinary tract specialist) is necessary to guide further tests and treatment. In the case of a cancer being present, management is dependent on the type of cancer, location and how advanced it is (the stage), but the main types of treatments include surgery, radiotherapy, chemotherapy and immune therapy.