Since 1998, federally subsidized student loans have been non-dischargeable in bankruptcy, except in rare cases involving permanent disability or death.

CNN: Obama should push bankruptcy relief for student loans

Natural measles infection, while not harmful to most children, carries a slight risk of permanent disability - or even death.

BBC: Childhood measles may protect from asthma

To try to stop the cancer spreading, 10 centimetres of nerve was removed - causing permanent disability below the right knee.

BBC: The boy, 11, who battled cancer twice in one year

He wants to get permanent disability, essentially a medical retirement with a pension and lifetime health insurance for him and his family.

NPR: Wounded Soldier Fights for Health Benefits

This reduces the damage, although frequently it cannot prevent some permanent disability.

BBC: Surgery hope for unborn babies

It is thought to be a cause of many falls among the elderly, leading in some cases to fractures which cause permanent disability.

BBC: Feeling faint? Cross your legs

The symptoms of ME include chronic fatigue, muscle pains and migraine, but in extreme cases patients can develop a permanent physical disability.

BBC: Doctor and child

Left with some permanent health issues and on disability for a time, she was lucky to find a job she can do at home.

FORBES: Straying Off the Path or Changing Direction?

But much of the gap represents permanent departures from the labour force because of early retirement or workers going on disability benefit.

ECONOMIST: Free exchange