l Pulmonary fibrosis causes the lung tissue to thicken and become stiff, while the scarring stops oxygen from entering the blood stream.
l If it is not known what has caused the condition, it is called idiopathic pulmonary fibrosis – IPF.
l Symptoms can include a chronic dry, hacking cough, fatigue and weakness, discomfort in the chest, loss of appetite and rapid weight loss.
l The only cure for the disease is a lung transplant.
l The number of cases seems to be rising, but it is not clear why. It generally affects people in middle age, usually aged 50 and above, and is more common in men and among smokers.
l The condition is five to six times more common than cystic fibrosis, yet it remains virtually unknown to the public, many policymakers, and even some medical staff.
A GRANDMOTHER campaigning to raise awareness of a life-threatening lung disease told how living with the condition has been a gift as well as a curse.
May Stone has had idiopathic pulmonary fibrosis (PF) for the past five years, but had symptoms of the disease since 1998.
The 52-year-old, who carries an oxygen tank to help her breathe, set up a UK internet group for people with the condition and it receives 800 messages a month.
But she says there are people who still do not know the symptoms or enough about PF, which causes scarring on the lungs.
The only cure for sufferers is a lung transplant – and she has joined the increasing number of people backing the Evening Times campaign to persuade the Scottish Government to switch to a system for opting out, instead of the current opting in, for organ donation.
Mrs Stone, from Penilee, Glasgow, was diagnosed in 2006, after a lung biopsy. She was 47 and had been coughing constantly, experiencing breathlessness and feeling rundown since she was 40.
She said: "When I had my lung test I knew from the technician's face I had something serious.
"Everybody thinks if you are told your life is in danger you want to do things like climb a mountain or travel the world.
"But with PF you don't have the energy to do that. All I wanted to do was have lunch with people I like."
The administrator was forced to give up her job in 2007.
She added: "This makes you think about everything differently. It can be a gift because you don't sweat the small stuff. Nobody spends their life thinking about breathing - until the day you can't."
Medical experts do not know how people contract PF, but it can be linked to prolonged exposure to occupational or environmental contaminants or dusts.
Many workers who helped with the rescue and clean-up operation after the September 2001 terrorist attacks in New York were diagnosed with it after coming into contact with potentially lethal exposures, including building materials.
Mrs Stone, who is grandma to Thomas, 2, and five-month-old Maria, said the problem is finding the correct information about PF.
She said: "One of the first things you see when you are researching online about pulmonary fibrosis is that you are supposed to have a lifespan of three to five years.
"So, firstly, everybody thinks they have not gone long left. No matter what else you read, it is hard to get that out of your head.
"But the 3-5 year lifespan happens only with more aggressive forms of the illness.
"You can get a chest infection or pneumonia and be in trouble, but if you take care of yourself and learn from others who have it you can live quite a normal life."
Stewart Smith, from Newton Mearns, is also living with PF after being diagnosed in 2008.
The 64-year-old grandfather- of-three, said: "I had a cough that wasn't going away, even though I was taking antibiotics for it. I had an Xray at the Victoria Infirmary, which showed the scarring.
"I used to smoke but had given that up in 1974. The doctors told me it was not connected to that – they think it is to do with the immune system."
DUE to the lack of information available on the little-known lung disease, May has urged anyone with the condition to get in touch.
Mrs Stone, who is married to Andy, 50, said: "Our UK online group is for anyone with PF. We have 250 members up and down the country. We are a baby group compared to others, we are the pioneers."
Mr Smith added: "When you compare it to other illnesses, such as cancer, PF is virtually unknown. Some cancers are curable, this isn't. We need to raise awareness."
The pair are also urging people to sign the Evening Times' petition to persuade the Scottish Government to switch to an opt-out system of organ donation.
Mrs Stone added: "More people are going to need a transplant, so if you would not hesitate in accepting one then everyone needs to be willing to give one. I am completely behind the campaign."
The UK run Yahoo Online Group can be accessed by subscribing to: firstname.lastname@example.org or by visiting: tinyurl.com/pfuk123