A disease in which the walls of the alveoli are progressively killed, thereby reducing the area of lung available for exchange of gases. The alveoli, of which there are millions in either lung, are groups of air sacs at the end of bronchioles (tiny air passages). Through their thin walls, inhaled oxygen is passed down into the bloodstream and carbon dioxide is taken out from the capillaries to be breathed out.
Emphysema often occurs along with chronic bronchitis in a condition that is known as chronic obstructive pulmonary disease, also known as COPD.
In the majority of cases, emphysema is a direct result from smoking. In extreme cases, an inherited deficiency of a chemical called alpha antitrypsin in the body leads to emphysema and, in a minority of people, also can affect the liver.
Air pollutants and tobacco smoke are suspected to cause symptoms of emphysema by stimulating the release of chemical within the alveoli that create damage to the alveolar walls. Alpha-antitrypsin is expected to protect against the chemical injury; therefore , people with a deficiency of this substance are especially affected by emphysema.
The damage is minor in the beginning, but in heavy smokers it becomes progressively worse’ the alveoli burst and merge to create fewer, bigger sacs with less surface area, which subsequently impairs carbon dioxide and oxygen exchange. Over the years the lungs become more and more less elastic, which further decreases their efficiency.
Symptoms and signs
First off, there are no apparent symptoms, but as the disease progresses and the lungs undergo damage, there some increasing shortness of breath. In certain people, the chest becomes barrel-shaped as air is trapped in the lungs. There can also be a chronic cough (brought on by the accompanying bronchitis) and a slight wheeze.
In the end (sometimes after many years) the level of oxygen in the blood begins to fall. In certain cases pulmonary hypertension occurs, leading to cor pulmonale (strain and enlargement on the right side of the heart). Affected persons start to turn blue due to a lack of oxygen in the blood; their legs consequently swell as a result of oedema. Other people are able to compensate for oxygen deficiency to a certain extent by breathing more rapidly, thereby retaining their usual colouring. Most sufferers display signs of falling somewhere between these two extremes.
A diagnosis is confirmed from the person’s symptoms and signs, from a chest examination, and from a variety of tests. A blood sample from an artery can be analysed to measure the concentration of carbon dioxide and oxygen in the blood; blood oxygen levels could alternatively be measured using an oximeter. A blood test for alpha-antitrypsin deficiency can be carried out if there is a family history of the disorder. Chest x-rays are taken to eliminate the chance of another lung disease being responsible for the symptoms and to understand how great an area of the lung has been affected. Pulmonary function tests are undergone to asses breathing capacity and the efficiency of the alveoli in exchanging gases.
Treatment and prevention
After the damage to the lungs has taken place, there is no treatment that is able to reverse it. But, giving up smoking will heavily reduce the rate at which the lungs deteriorate. The effectiveness of the remaining lung tissue can be improved in a variety of ways. For example, bronchodilator drugs could be administered to broaden the bronchioles. A corticosteroids inhaler can be prescribed to help prevent flare ups of the symptoms of COPD, and those who are deficient in alpha-antitrypsin therapy.
In an infection occurs, antibiotic drugs can be prescribed, and if there is oedema, diuretic drugs can assist to reduce the volume of fluid in the body, by promoting its output through raised levels of urine production. If the blood oxygen level is consistency low, oxygen therapy at home may be required.
Those who have a localised area of emphysema in one lung could be offered surgery to get rid of the affected area of tissue, which can then allow the remaining lung tissue to re expand. A single lung transplant operation can be considered of respiratory failure is life-threatening.