COPD (Chronic Obstructive Pulmonary Disease) is a general term which refers to chronic bronchitis and emphysema, a pair of two commonly co-existing diseases of the lungs

Chronic bronchitis: bronchitis means 'inflammation of the bronchi'. These are the tubes or airways which carry oxygen from the air through the lungs. This inflammation increases mucus production in the airways, producing phlegm which makes you cough.

Emphysema: this is where the alveoli (air sacs) in the lungs lose their elasticity. This reduces the support of the airways, causing them to narrow making it harder for air to get in and out of the lungs. It also means the lungs are not as good at getting oxygen into the body, so you may have to breathe harder. This leads to a limitation of the flow of air to and from the lungs causing shortness of breath.

COPD is common. About one million people in the UK have COPD. It mainly affects people over the age of 40. It accounts for more time off work than any other illness. A flare-up (exacerbation) of COPD is one of the commonest reasons for admission to hospital. It causes around 5% of all deaths each year in the UK and is the fourth leading cause of death in the USA and Europe.

Smoking is the cause in the vast majority of cases. There is no doubt about this. The lining of the airways becomes inflamed and damaged by smoking. About 3 in 20 one-pack-per-day smokers and 1 in 4 two-pack-per-day smokers develop COPD if they continue to smoke. Air pollution and polluted work conditions such as coal dust may cause some cases, or make the disease worse. Whether pollution is a factor is under investigation. However, people that have never smoked, rarely develop COPD.

• Cough is usually the first symptom to develop. It is productive with sputum (phlegm). It tends to come and go at first, and then gradually becomes more persistent (chronic). You may think of your cough as a 'smokers cough' in the early stages of the disease. It is when the breathlessness begins that people often become concerned.
• Breathlessness ('short of breath') and wheeze may occur only when you exert yourself at first, for example, when you climb stairs. These symptoms tend to become gradually worse over the years if you continue to smoke. Difficulty with breathing may eventually become quite distressing.
• Sputum - the damaged airways make a lot more mucus than normal. This forms sputum (phlegm). You tend to cough up a lot of sputum each day.

Chest infections are more common if you have COPD. Wheezing with cough and breathlessness may become worse than usual if you have a chest infection. Sputum usually turns yellow or green during a chest infection.

Some people may only notice their symptoms in winter, or they might put them down to bronchitis or ‘smoker’s cough’. This means that they might not seek help at an early stage of the disease. The sooner people seek treatment the better.

The best way to confirm diagnosis is through spirometry. This is a simple breathing test which you can usually do at your GP’s surgery. This test measures how much air you can blow into a machine. A value is calculated from the amount of air that you can blow out in one second divided by the total amount of air that you blow out in one breath. A low value indicates that you have narrowed airways. A low value combined with the typical symptoms of COPD usually confirms the diagnosis. In some cases you may need more detailed tests and a referral to hospital for more in depth breathing test and/or  a C T Scan.