IT’S REALLY NOT FUNNY!

PRIAPISM — a painful erection that doesn’t go down for several hours — sounds like something a man with impotence might dream of. In fact, it’s no joke, says Professor Mike Kirby.

If you have an erection that lasts more than four hours, it’s painful and extremely dangerous. It means the tissues in the penis are dying, so he advises going straight to A&E

And even if they last less than four hours, help should still be sought.

Erections happen when a man’s nervous system releases nitrous oxide, a chemical that relaxes the arteries supplying blood to the penis. As arousal passes, the arteries contract again, forcing out the blood.

But some drugs and illnesses can interrupt this process, preventing fresh blood from entering the penis and starving tissues of the oxygen they need. Some antidepressants, including fluoxetine (Prozac), can cause prolonged erections, as can blood-thinning drugs such as warfarin and heparin.

The latter can cause clots to form, which stop blood leaving the penis. Medical conditions that can trigger priapism include injuries to the spinal cord.

Sometimes, priapism simply goes away without treatment, but in other cases the blood has to be drawn off with a needle and any clots removed.

If this fails, the next step is an injection of a drug to squeeze the vessels in the penis, forcing out the blood.

Sometimes, surgery may be necessary, which involves inserting a ‘shunt’ to allow the trapped blood to bypass the blockage.