Which of the following is a characteristic of cystic fibrosis?

A characteristic of cystic fibrosis is the presence of a barrel chest. This respiratory condition affects the glands and causes the production of thick, sticky mucus that clogs the airways and leads to chronic respiratory issues. Over time, the effort to breathe against these obstructions can result in changes in chest shape, specifically a barrel chest appearance, which is the result of hyperinflation and poor lung function.

While chronic cough is commonly associated with cystic fibrosis as well, it is a symptom rather than a specific characteristic. Hyperinflation of the lungs can occur due to the mucus blockage, but it is not as definitive or diagnostic of the condition as barrel chest. Pulmonary fibrosis, on the other hand, refers to scarring of lung tissue and is not a direct characteristic of cystic fibrosis itself, although individuals with cystic fibrosis may have related complications. Thus, barrel chest stands out as a specific and observable characteristic in those with advanced cystic fibrosis.