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When the hematocrit rises to 60 or 70%, which it often does in polycythemia, the blood viscosity can become as great as 10 times that of water, and its flow through blood vessels is greatly retarded because of increased resistance to flow. This will lead to decreased oxygen delivery.
COPD, or chronic obstructive pulmonary disease, is a progressive disease that makes it hard to breathe. Progressive means the disease gets worse over time. COPD can cause coughing that produces large amounts of a slimy substance called mucus, wheezing, shortness of breath, chest tightness, and other symptoms. Cigarette smoking is the leading cause of COPD. Most people who have COPD smoke or used to smoke. However, up to 25 percent of people with COPD never smoked. Long-term exposure to other lung irritants—such as air pollution, chemical fumes, or dusts—also may contribute to COPD. A rare genetic condition called alpha-1 antitrypsin (AAT) deficiency can also cause the disease.
A chronic cough is a cough that lasts eight weeks or longer in adults, or four weeks in children. A chronic cough is more than just an annoyance. A chronic cough can interrupt your sleep and leave you feeling exhausted. Severe cases of chronic cough can cause vomiting, lightheadedness and even rib fractures. While it can sometimes be difficult to pinpoint the problem that's triggering a chronic cough, the most common causes are tobacco use, postnasal drip, asthma and acid reflux. Fortunately, chronic cough typically disappears once the underlying problem is treated.