Final answer:
Lung density can increase due to restrictive diseases like pulmonary fibrosis or obstructive conditions such as emphysema and asthma, leading to reduced lung capacity and difficulty breathing.
Step-by-step explanation:
Lungs can become too dense as a result of certain medical conditions that impact the lung tissue and its capacity to expand and contract. Two specific types of lung diseases are restrictive and obstructive diseases. In restrictive diseases, such as pulmonary fibrosis and respiratory distress syndrome, the lung tissue becomes stiff and less compliant, meaning it cannot bend and move easily. This leads to a decrease in the lungs' ability to expand, causing a diminished Forced Vital Capacity (FVC) and trapping air inside the lungs upon exhalation.
In obstructive diseases such as emphysema and asthma, the airways are narrowed or blocked, which also results in trapped air and difficulty breathing. Factors contributing to increased lung density include the formation of scar tissue, inflammation, and damage to the lung structures. For instance, exposure to harmful substances, such as diacetyl in popcorn factories, can lead to 'popcorn lung,' where the bronchioles are narrowed and breathing capacity is reduced.