COPD

COPD is long-term obstruction of airflow out of the lungs. Two things are happening together. The small airways are chronically inflamed, thickened and full of mucus, and the walls between the air sacs are destroyed so the lung loses its spring and the airways collapse as you breathe out. Air is trapped, the chest becomes over-inflated, and breathing takes more work than it should.

Unlike asthma, the obstruction does not open up fully with treatment. Lung tissue that has been destroyed does not grow back, so treatment aims at breathing more easily with the lung you have, slowing further decline and preventing the flare-ups that step the disease down.

Tobacco smoking is the largest cause worldwide. In India, smoke from cooking on wood, dung cakes, crop residue or coal in a poorly ventilated kitchen is a major cause in its own right, and it accounts for a large share of COPD in women who have never smoked. Occupational dust in stone cutting, construction and textiles, outdoor air pollution, severe childhood chest infections and previous tuberculosis all contribute. The breathlessness starts on hills and stairs and is often attributed to age or weight for years before anyone measures it.

The story does most of the work. Your doctor asks about breathlessness and how far you can walk on the flat before stopping, about cough and sputum, and above all about exposure: years of smoking, years of cooking on a solid fuel stove, dust at work. They are also asking how many times in the past year you have had a stretch of being much worse than usual, since flare-ups are what shape the treatment.

On examination they look at how hard you are working to breathe, the shape of the chest, the movement of the ribs and the use of neck muscles, and they listen for reduced air entry. Your oxygen level is measured with a clip on the finger, and your weight and muscle bulk are noted, since losing both is common and matters.

The diagnosis is confirmed by a breathing test, before and after a reliever, which shows obstruction that does not fully reverse. A chest X-ray, a blood count and a sputum test for tuberculosis are usual, because previous or active tuberculosis is a frequent and treatable part of the picture in India.

Nothing here restores the lung, so the measure is how much better your day gets and how well the decline is slowed. Stopping the exposure is the only intervention proven to change the rate of decline, and that means stopping smoking and getting the cooking smoke out of the kitchen. The benefit starts within months and continues for years.

Inhalers ease breathlessness within days and are judged at four to six weeks by what you can do, not by how the test reads. A pulmonary rehabilitation programme, which is supervised exercise and education two or three times a week for six to eight weeks, reliably improves walking distance and breathlessness, and it does more for most people than any additional medicine. The gains fade if the exercise stops, so it continues at home.

A flare-up takes two to six weeks to settle, and a proportion of people never quite get back to the level they were at before it. Vaccination against influenza and pneumococcus is offered for that reason.