What is an inflammation of the lungs caused by infections?

Pneumonia is an inflammation of the lungs that is primarily caused by infections, which can include bacteria, viruses, or fungi. In pneumonia, the air sacs in the lungs fill with fluid or pus, making it challenging for the body to oxygenate the blood efficiently. Patients commonly exhibit symptoms such as cough, fever, chills, and difficulty breathing. This condition is particularly severe in vulnerable populations, such as the elderly and those with weakened immune systems.

The other conditions listed, while related to respiratory issues, do not specifically describe an inflammation of the lungs caused by infections. Bronchitis involves inflammation of the airways leading to cough and mucus production but can occur without an infectious cause. Emphysema, a form of chronic obstructive pulmonary disease (COPD), involves destruction of the lung tissue and is primarily associated with smoking rather than infections. Asthma is characterized by airway hyperreactivity and inflammation, often triggered by allergens or irritants, not typically by infections. Thus, pneumonia stands out as the correct answer to describe lung inflammation specifically caused by infections.