Hopefully you won't get one big enough to block your kidney, or that requires a stent, or lithotripsy.

In an age before anaesthesia and antiseptics, lithotomies were often fatal. Samuel Pepys was so glad to survive his that he placed his stone in a reliquary and threw a party for it every year. Others set their stones into jewellery and printed cards commemorating their surgery. Those less determined to defy death resorted to quack medicine or even scraping their insides with wire. Benjamin Franklin, as usual, outdid everyone. When stones blocked his urethral opening, he dislodged them by standing on his head and urinating upside down.

BENJAMIN FRANKLIN had plenty of company in his medical miseries Isaac Newton also suffered from bladder stones, as did Peter the Great of Russia and Napoleon Bonaparte. Bladder and kidney stones were once a far more common affliction than they are today. Indeed, Franklin's brother also had stones, and when Ben designed a draining catheter for his blocked bladder, his relief was so immense that he had another made and sent it to his brother with his compliments. And while some sufferers passed their stones relatively painlessly, others were less fortunate, suffering excruciating pain, vomiting, fever, bloody urine and permanent kidney damage.