NEXT Wednesday, Katrina Field-Thomas will celebrate her 40th birthday.

Nothing unusual about that you might think... but when you hear that Katrina was diagnosed with cystic fibrosis when she was just a few months old and given just five years to live, you begin to realise what an achievement it is.

Since that time she has undergone an intense course of treatment, including a daily routine of medication and physiotherapy, but she has defied all the odds and continues to amaze the medical experts.

Indeed, Katrina, of 5 Churchill Close, Tenby, is an inspiration to all in the way she has courageously battled against this debilitating disease.

And perhaps appropriately, born on February 25, 1964, Katrina's birthday comes in the same year as the CF Trust also marks its own 40th anniversary.

Over the years, research into cystic fibrosis has brought about new treatments and sufferers are now living longer.

But, even so, as she gets older, living with CF is becoming harder for Katrina.

"Every day is a battle," she told the Observer this week. "Some days are a real struggle and I feel as if I have had enough, but then there is something else inside telling me to keep going."

"Although you do not see many CF sufferers reaching the age of 40, they are living longer and the drugs and the treatments that are available now mean patients will have a much better quality of life than before," added Katrina's husband Gavin, who hopes that Katrina's story will give hope to other CF sufferers.

One of the proudest next Wednesday, would have been Katrina's late father, John, who she says was her 'backbone'.

"He was fantastic and when I was young he really kept me going," she said.

And Katrina was full of praise, too, for the doctors and nurses who have helped her over the years, particularly Dr. Roberts at Tenby Surgery and the staff at Glangwili Hospital, Carmarthen.

"They have all been marvellous," she added.