If you're thinking about giving up smoking then here's another reason to quit the habit.
Scientists have warned about the ill effects of nicotine addiction on your health and size of your penis.
Smoking could have a negative impact on the size of men's erections and even make the penis shrink.
According to experts, there are a number of lifestyle factors which can impact tumescence – or erectile firmness.
Speaking exclusively to MirrorOnline , experts have revealed the effects of smoking on men's penises, including shrinkage and erectile dysfunction.
Marc Laniado, Harley Street urologist, explained: “I see erectile dysfunction a great deal.
“To have a firm erection, you need sufficient blood flow.
"Smokers have a higher incidence of artherosclerosis in all blood vessels, including those in the penis, which can reduce blood flow.
“The chemicals in smoke may also have an effect on firmness; nicotine causes blood vessels to become narrow. This can be temporary or – eventually – permanent.”
Worryingly, smoking cigarettes can also cause the penis to shrink over time.
Mr Laniado explained: ”Often they will say ‘my erection is not so good, I don’t wake up with an erection in the morning as much as I used to or my penis isn’t quite so hard when I’m having sexual relations'.
“But also sometimes people say that their penis is getting shorter as they get older, as smoking stops the blood flowing through the penis, which stops the spontaneous and nightly erections that are needed to stretch the penis and keep it at a good length.
“So in summary smoking can make your penis appear shorter or in fact become shorter.”
And before female smokers get complacent, Mr Laniado added that smoking can also affect their sex lives.
He added: “Women’s arousal is – if you think about it – also affected by blood flow to the area.”
Mr Laniado’s warning comes as part of Vice's Change Incorporated mission to get people in the UK to quit smoking cigarettes for good.