Disease pattern & symptoms
Patients with an overactive bladder (OAB) constantly feel the need to go to the toilet, even though hardly any fluid has collected in the bladder. The urge to urinate usually comes so suddenly that micturition – urinating – cannot be postponed for a moment. If the way to the toilet is long, urine may also be lost involuntarily.
Normally, as soon as a certain filling state of the bladder is reached, receptors send a signal to the brain, thus announcing the need to urinate. This stimulus is triggered until it is yielded to and the bladder is emptied. This process is disturbed in people with an overactive bladder. The bladder muscle is active much earlier in affected individuals, resulting in a more frequent need to urinate and thus to use the toilet (at least eight times per day). This can be a great burden, especially during the night.
The following symptoms may occur with OAB:
- Increased urge to urinate
- Frequent visits to the toilet with a low amount of excretion
- Involuntary leakage of urine (urge incontinence)
- Nocturnal urination
- Often pain sensation due to the constant state of irritation
Urge incontinence is generally manifested by involuntary leakage of urine due to an uncontrollable, sudden urge to urinate (imperative urination). In principle, a distinction is made between two forms, based on the cause of urge incontinence:
- Motor urge incontinence (overactive bladder)
The cause of this form of incontinence is a lack of inhibition of the nerve impulses of the bladder muscle, resulting in repetitive uncontrolled, spasmodic contraction of the bladder muscles. This results in recurrent urinary leakage. However, an overactive bladder and the motor urge incontinence that often results from it can also occur without any apparent causes.
- Sensory urge incontinence (hypersensitive bladder)
In this form of urge incontinence, there is a faulty transmission of information between the brain and the bladder. The brain mistakenly receives the signal that the bladder needs to be emptied due to the advanced state of filling, when in fact it contains hardly any fluid. As a result, the brain induces contraction of the bladder muscle, which often results in urine leakage.
 Urology Care Foundation