You'll go blind.......

So let's discuss the Long-Term Effects of Masturbation.

Uncyclopedia.wikia.com has the following advise:

The long term effects of masturbation include hairy palms and, if continued after this point, lycanthropy. It is a documented fact that all werewolves were prolific wankers. Scientists estimate it takes approximate 1,995.67 wanks to transform a person into a werewolf.

Other noted effects are:

Forgetfulness and/or possible memory loss.
Weight loss - follow the techniques of onanibics and masturbate to lose weight.
Poor eyesight due to the fact that porn has been proven to be very hard on the eyes.
Forgetfulness and/or possible memory loss.
Addiction, for which there is the support group "Wankaholics Anonymous".

And remember there are obvious physical ramifications too:

So all i'll add to this, is it might seem like a good idea at the time, but think twice before you put yourself at risk :)