Effects, Causes and Symptoms

Emphysema is a chronic, progressive lung disease that develops when the small air passages leading to the alveoli (the tiny air sacs in the lungs, where gas exchange takes place) become distended and the walls dividing the alveoli are injured or destroyed. Spaces form where alveoli had been, and lung tissue becomes nonfunctional and stiff rather than elastic.

Emphysema is considered to be a type of chronic obstructive pulmonary disease (COPD). It is commonly associated with chronic bronchitis, in which the airways become inflamed, causing specialized cells within them to secrete abnormally large amounts of mucus. The inflammation, swelling, and excessive mucus production result in obstruction of airflow and entrapment of air within the lungs.

Emphysema is a chronic, progressive lung disease involving damage to the alveoli.

Emphysema is a chronic disease in which the alveoli become overinflated with trapped air.

Effect on the Body

As the disease progresses, many complex changes take place, ultimately leading to diminishment of the amount of oxygen in the blood, frequently associated with an increased amount of carbon dioxide. As the lung tissue deteriorates and loses its elasticity, changes also occur in the blood vessels carrying deoxygenated blood to the lungs for a fresh supply of oxygen. The net effect is that the right side of the heart, which is responsible for collecting deoxygenated blood from the veins of the body and pumping it through the lungs, must work much harder.

As the process continues, the muscle of the right side of the heart is weakened by this extra work and becomes less able to pump blood into the lungs. The blood backs up, causing increased pressure in the veins. This, in turn, causes fluid to recede into the tissues, resulting in severe swelling of the feet, ankles, and legs. If this right-sided heart failure (also known as cor pulmonale) is very severe, the abdomen will become distended with fluid.

Causes

External factors that irritate the lungs, such as tobacco smoke and air pollutants, are commonly linked to emphysema. Unlike many respiratory diseases, emphysema is not caused by a viral or bacterial infection. However, it is often aggravated by a case of bronchitis or another lung infection.
In a minority of cases, emphysema is a result of a genetic deficiency or an inherited lack of a specific blood protein, which leads to loss of elasticity in the alveoli.

Those afflicted with emphysema are most likely to be white men older than the age of 50, although the number of women who are susceptible has risen dramatically because of an increase in smoking among women during recent decades. The overwhelming majority of emphysema cases have been directly linked to cigarette smoking.

Symptoms

Emphysema is characterized by one major symptom -- shortness of breath. Patients may also have a persistent, racking cough, which either brings up mucus or is overly dry. Patients experience difficulty in breathing, often taking twice as many breaths as healthy individuals would in order to get enough oxygen. It has been found that advanced emphysema sufferers exert tremendous amounts of energy just in the act of breathing. They also tend to tire quite easily and require more calories to maintain their weight than healthy individuals do.

An enlarged, rounded barrel chest often develops due to overinflation of the lungs and excessive growth of the chest muscles as a result of the increased stress placed upon the muscles to inflate stiff lungs. Lips, ear lobes, skin, and fingernails may be tinged blue from lack of oxygen in the blood.

In the next section, we will review the diagnosis and treatment of emphysema.