Chronic Obstructive Lung Disease - Complications

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Low oxygen levels also can impair mental function and short-term memory. Psychological therapy may be particularly helpful for people with COPD.

Malnourishment

People with COPD often lack good nutrition. Patients with chronic bronchitis tend to be obese. Patients with emphysema tend to be underweight. Loss of weight and muscle mass is linked to a poor outcome in COPD. Good nutrition improves the ability to exercise, which in turn builds muscle strength and lung function. Obese patients with COPD who lose weight tend to sleep better.

Heart Disease

Over time, COPD causes low levels of oxygen (hypoxia) and high levels of carbon dioxide (hypercapnia) in the body. In order to boost oxygen delivery, the body compensates in a number of ways:

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• Blood vessels in the lung narrow. This leads to high blood pressure in the lungs (pulmonary hypertension).
• More red blood cells are produced to increase the blood's ability to carry oxygen.
• The heart rate increases to pump more blood.
• The breathing rate increases.

Eventually these activities can lead to very serious and even life-threatening conditions:

• Abnormally high blood pressure in the lungs can cause a complication called cor pulmonale. The right ventricle of the heart enlarges, eventually leading to heart failure.
• Chronic bronchitis is associated with a 50% higher risk of death from coronary artery disease, independent of the risks associated with smoking.
• Patients with long-term and severe hypoxia and hypercapnia are at risk for acute respiratory failure, which can cause heart rhythm abnormalities or other life-threatening conditions.

Other Serious Medical Problems Associated with COPD

The smoking that causes COPD is associated with high risks of pneumonia, lung cancer, stroke, and heart attack. Tobacco smoke contains more than 400 substances, many of which are oxidants, metals (such as lead, cadmium, and aluminum), and cancer-causing chemicals (carcinogens). Nicotine itself may not damage tissues, but it addicts smokers to tobacco.

Lung Cancer. Patients with a 30-year history of smoking and signs of limited airflow (most patients with COPD) are at high risk for lung cancer.