Not only are you in considerable pain and discomfort, but you know that there is every possibility that the disease could kill you.
That was the reality for people everywhere not so long ago. But sufferers in 1936 had a great reason to celebrate: a hospital dedicated to saving them and others laid low by chest diseases was opened on the coastline at Sully.
It immediately proved a great success, and for years treated thousands of people in pleasant woodland surroundings overlooking the Bristol Channel.
Word of its high-quality treatment for so called "blue babies" struck by "the white plague" of TB, and youngsters suffering heart and chest problems, spread worldwide. But its popularity and reputation rapidly led to a nursing shortage.
By 1952, 60 beds were regularly lying empty due to a lack of carers for those recovering from surgery, and Sully had to issue an urgent appeal for more recruits in order to prevent the beds remaining permanently closed.
Improvements in medicine led to a decreasing number of TB cases, and in 1959 the hospital set aside 100 of its 324 beds for non-TB patients.
That number steadily increased as its doctors began earning praise for their heart surgery, which involved using some equipment bought from chain stores and the selloff of former Spitfire parts.
Doctors from around the world visited Sully, which for a time was the site of the Welsh School of Medicine's TB department.
Other facilities were supported by donations from the public, including a pounds 500 appeal for an open-air swimming pool for the staff that was completed in the mid1960s.
However, the situation changed in 1973.
Heart surgery moved to the University Hospital of Wales at the Heath and acute thoracic cases to Llandough Hospital.
After lengthy debate, and protests from local residents and campaigners, it was decided that Sully would take geriatric patients and specialise in respiratory medicine.
But staff became increasingly concerned about a lack of resources and doubtful about the site's long-term future.
In 1977 William Evans, secretary of the Vale of Glamorgan Community Health Council, hit out after plans were unveiled to move psychiatric patients from Bridgend to Sully and then, he said, to Llandough.
If they went on to Llandough, he warned: "Sully will have no role and no future. It will become a dumping point."
And local doctor Gordon Williams said: "We suspect they are trying to close it."
The following year, only 164 of Sully's 202 beds were occupied, with 60 chest patients, 32 cardiology, 37 geriatric and 73 psychiatric.
Staff claimed the health authority was gradually running Sully down, and said that if it only housed the chronically sick, consultants and staff would be deterred from working there.
The authority replied: "There are no plans to run it down or turn it into a hospital only for the chronically sick, but it could become one of the best general hospitals in the next 10 years."
Hopes that Sully could be developed into a top orthopaedic centre were dashed when it had to accommodate patients from rundown Rhydlafar Hospital, and in 1981 it opened a psychiatric unit with 90 beds.
Hospital a setting for many events
THROUGHOUT its long life, Sully Hospital enjoyed an important part in the local community and strong ties with residents.
And besides regular healthcare, it was the setting for many different events:
The Jane Hodge Trust and cancer group Tenovus stepped in to arrange the transfer of pounds 160,000 worth of X-ray facilities from a Cardiff hospital to Sully in 1987.
The 1988 replacement of traditional breakfast fry-ups with light continental breakfasts sparked a 200-signature petition from staff who said it was a sign of falling standards.
In 1991 a highly realistic mural of a 1930s grocer's store was used as a pioneering example of how artwork could help patients' treatment.
A row broke out in 1990 when it emerged that doctors launched human drug trials at Sully without receiving the go-ahead from top officials.
The breach of regulations was made public when a nurse was stabbed by a psychiatric patient undergoing a drug trial - although an investigation decided the experimental medicine was not linked with the attack.
Staff who worked during a 1989 strike were invited to see The Pirates of Penzance at the New Theatre, with the health authority footing the bill.
But the trip was scrapped after criticism from those who went on strike, among others.
In 1995, a psychiatric patient was found drowned at Hayes Point, up to three days after walking out of the hospital grounds.
Supporters spent pounds £4,000 in 1995 on a secret garden, a haven of peace and quiet where patients could enjoy the fresh air.
Operations made history at hospital
HISTORY was made at Sully Hospital, as its doctors often took part in pioneering or unique operations.
It was at Sully, for instance, that surgeons practised a "deep freeze" technique to help prevent the damage to organs that could be caused by any interruption to the blood supply.
Doctors learned how to cool patients so they could be put into semi-hibernation, which meant the organs required less oxygen, slowing down the heart and preserving organs.
In 1951 a doctor at Sully won great acclaim after going against general medical beliefs and carrying out a chest operation on a three-year-old boy suffering from TB.
According to surgeons of the time, a procedure like that on the lungs of such a young child was unsafe.
But the Sully doctor persevered and, in a 60-minute operation, saved the youngster's life.
The hospital also conducted vital research using animals.
As part of a study into how to carry out lung transplants, in 1964 doctors managed to conduct a number of the operations - and then analyse the after-affects - using sheep bought from local farmers.