Smoking exacerbates incontinence, especially in women.
This happens via many mechanisms.
The main one is that chronic smokers are often affected by coughing, which increases intra-abdominal pressure and leads to urinary incontinence that may range from just a few drops to larger quantities, each time the patient coughs.
It is also known that many of the substances contained in smoke from burning cigarettes are expelled in urine.
Some of these substances are very irritating for the mucosa of the urinary bladder and lead to hyperreflexia of the urinary bladder which, in turn, causes urinary incontinence.
Lastly, smoking causes dryness in the female genitals and, as a result, dries out the urethra.
An additional incontinence mechanism in women is what, in English-speaking literature, is known as the “seal mechanism”.
With this mechanism, the moisture of the urethra mucosa leads to the walls of the urethra to stick together, a phenomenon similar to that of two wet plastic bags that cannot be easily separated.
Am.J.Obslet Gyneol.1992 Nov 167(5):1213-8.