The size of the problem
* Britain's tallest man, Chris Greener, 7ft 6Ein, was already 6ft 3in when as a 14-year-old schoolboy he was asked by the school careers adviser what he wanted to do with his life. Chris said he'd like to join the Royal Navy.
"What do you want to be?" asked the unsympathetic master, looking him up and down. "A mast?" Most tall people have tall parents to thank for their stature, but supertall Chris, like others among the world's tallest, gains his height from a pituitary gland problem. And he is happy with his lot. "It's great being this size," he says. "It wouldn't be so great being the second tallest. "
* The world's tallest man, Alam Channa, 7ft 7E in, is currently lying stricken with pain on two beds laid end-to-end in a Pakistan hospital.
Alam desperately needs specialised treatment for height-related complications - one kidney has failed, he is diabetic, and his feet and hands are swelling. But the limited facilities of his homeland mean he may have to travel to the USA for surgery.
That would cost money he doesn't have - and Alam's position is worsened by the hangers-on who surround him and attempt to profit from living in the shadow of his fame.
"It is a blessing from God to be so tall," says Alam, aged 44 and weighing 28 stone. "And a curse."
* Sandy Allen, of Chicago, USA, is the world's tallest living woman, at 7ft 7Ein tall. She had reached 6ft 3in by the age of 10, and was 7ft 1in when she was 16.
* The tallest man in history was Robert Wadlow, of Alton, Illinois, USA. Born in 1918, he was a shade over 8ft 11in and still growing when he died at the age of 22. His hands measured almost 13 inches from the wrist to the tip of the middle finger.