What is chronic bronchitis characterized by?

Chronic bronchitis is primarily characterized by persistent inflammation of the bronchial tubes, leading to an overproduction of mucus. This condition falls under the umbrella of chronic obstructive pulmonary disease (COPD) and is often associated with long-term exposure to irritants such as tobacco smoke or environmental pollutants.

The inflammation in the airways causes the lining to thicken, which in turn increases mucus production. This excess mucus can obstruct airflow and make it difficult for the individual to breathe, contributing to coughing and wheezing. The hallmark of chronic bronchitis is a productive cough that lasts for at least three months over a span of two consecutive years. This distinguishes it from other respiratory conditions where shortness of breath or reduced lung function might be more prominent.

While aspects such as reduced lung elasticity, shortness of breath during exertion, and the inability to breathe deeply can all be associated with chronic bronchitis and other respiratory illnesses, they do not specifically define this condition. The key feature of chronic bronchitis is the chronic inflammation and overproduction of mucus, making it the most accurate description among the given choices.