In stress incontinence, a variable amount of urine escapes suddenly with an increase in intra-abdominal pressure (for example, when the abdomen tenses). Not much urine is lost, unless the condition is severe. This type of urinary loss is predictable. People with stress incontinence do not usually have urinary frequency or urgency (a gradual or sudden compelling need to urinate) or need to wake up at night to go to the bathroom (nocturia).
With urge incontinence, or overactive bladder, there is uncontrolled urine loss associated with a strong need to go to the bathroom. While the urge to urinate may be gradual, it is often sudden and rapid and occurs without any warning. Urge incontinence cannot be prevented. In this situation, the entire contents of the bladder are lost rather than a few drops of urine. People with overactive bladder feel the intense need to urinate and are unable to hold back the urine. Other symptoms include frequent urination, urgency, and nocturia. Some situations trigger urge incontinence, including turning a key in the door, washing dishes, or hearing running water. Urge incontinence also may be triggered by drinking too much water or drinking coffee, tea, or alcohol.
This type of incontinence includes the symptoms of stress incontinence and urge incontinence together. With mixed incontinence, the problem is that the bladder is overactive (the urge to urinate is strong and frequent) and the urethra may be underactive (the urine cannot be held back even without the urge to urinate). Those with mixed incontinence experience mild to moderate urine loss with physical activities (stress incontinence). At other times, they experience sudden urine loss without any warning (urge incontinence). Urinary frequency, urgency, and nocturia also occur. Most of the time, the symptoms blend together, and the first goal of treatment is to address the part of the symptom complex that is most distressing.
In overflow incontinence, the urine overflows from the bladder because the pressure inside the bladder is higher than the urethral sphincter closure pressure. In this condition, there may be no strong urge to urinate, the bladder never empties, and small amounts of urine leak continuously. Overflow incontinence is prevalent in older men with an enlarged prostate and is less common in women. Because the bladder is too full, the bladder empties even though the bladder muscle may not contract.
Overfilling of the bladder can occur if the outlet from the bladder is obstructed so urine backs up in the bladder or if the bladder muscle does not work so urine is not completely expelled from the bladder during urination. People with overflow incontinence may feel like the bladder does not empty completely, their urine flows out slowly, and/or that urine dribbles out after voiding. Symptoms of overflow incontinence may be similar to those of mixed incontinence. A small amount of urine may be lost when intra-abdominal pressure is increased. There may be symptoms of frequency and urgency as the detrusor muscle attempts to expel urine.
People with functional incontinence have relatively normal bladder function and control. Other conditions separate from the bladder affect their ability to reach the toilet in time.