THERE are 6,144 people waiting for organ transplants in the UK. This year 400 of them will die before a suitable donor organ is found.

Glen Wareham from Southampton is one of 5,339 people on the waiting list for a new kidney.

For him, like everyone else in need of life-saving transplant surgery, the clock is ticking - and he's just 25.

Last year 1,230 organ transplant operation were carried out, leaving a huge number of people still on the waiting list.

Britain is facing a transplant crisis. Quite simply, there's a huge gulf between the number of people waiting for an organ transplant and the number of organs available.

And, due to a number of factors, that gulf is widening.

An ageing population who need transplants and an increase in kidney failure are two major factors in the growing disparity between the number of patients needing transplants and donor organs.

The problem is compounded because very few people die in circumstances where their organs can be donated. That's because of the speed at which transplantation has to take place.

Organs can only be donated by people who die in hospital and usually come from someone who has been certified dead while on a ventilator, generally as a result of a car crash, brain haemorrhage or stroke.

The good news is that fewer people are dying in these circumstances, because of improvements in road safety and medical techniques.

But this leaves a problem - organs are not available for transplant.

"There is a critical shortage of organs available for transplant purposes on the UK," said Bob Corfield from UK Transplant, the only Special Health Authority within the NHS with a UK-wide remit, whose key role is to ensure that donated organs are matched and allocated in a fair and unbiased way.

By far the longest waiting list is for kidneys. "Transplantation of a kidney is a very effective treatment for kidney disease, which is on the increase due to many reasons - diet, people living longer, and so on," added Mr Corfield.

Glen Wareham, who desperately needs a new kidney, is on the waiting list at St Mary's Hospital in Portsmouth, which has a specialist kidney transplant unit.

He is one of 160 people waiting for a lifesaving transplant at the hospital, which carried out 50 such operations last year.

According to UK Transplant, one of the major causes of the growing transplant crisis is that the next of kin do not know the wishes concerning organ donation of deceased loved ones.

UK Transplant runs a national register of people who want to donate their organs, which has taken over from the old donor card system.

But just registering your wishes is not always enough to ensure that someone will benefit in the event of your death.

"Our main message is for people to sign onto the organ donation register and talk about it with the family so that if the time ever comes, your wishes are known to your family.

"That can make the question of organ donation much easier to answer in the positive," said Mr Corfield.

Dr Magi Sque, from the University of Southampton, agrees.

She is currently carrying out research into people's reasons for refusing to allow a relative's organs to be donated after their death and their feelings about it.

"The most important reason for people not donating is because they know that their relative didn't want their organs donated, so in these cases it's very clear cut," she said.

"But we know that if surviving relatives know their loved one's wishes, even if they are against donation themselves, they would allow it to go ahead because they would choose to fulfil their loved one's wishes."

At the moment, only about 20 per cent of the population are registered as organ donors.

"If the families of everyone who died in circumstances where their organs could be donated agreed to donation there would still be waiting lists but they would be massively cut," said Mr Corfield.

Organ transplantation is a life-saving operation, but what does it mean for the patients' quality of life?

"After transplantation, patients can see an immediate improvement. Their quality of life can be restored to what it was like before they fell ill," said Debbie Wilson, transplant co-ordinator at St Mary's Hospital.

"By increasing the number of donor organs available we can improve the quality of life for a large number or people."

If you wish to sign up on the organ donor register, call 0845 1616400 or visit www.uktransplant.org.uk