Overflow incontinence involves the involuntary release of urine from an overly full urinary bladder, that has retention of urine, often in the absence of any urge to urinate.

• It is due to an overly full bladder, often in the absence of any urge to urinate
• It is as if their bladders are constantly "overflowing"

• Blockage of the bladder outlet, making it so that urine has no where to go. It includes prostate cancer, narrowing of the urethra
• Weak bladder contraction (specifically, of the detrusor urinae muscle), making it unable to empty the bladder normally
• Side effect of certain drugs

• Cholinergic, e.g. bethanechol
• Catheterization, to drain urine from the bladder

• Urinary incontinence (category)