Which of the following is a risk factor for ARDS?

• A. Hypertension
• B. Aspiration
• C. Hypothyroidism
• D. Seasonal allergies

Answer: (B)

ARDS happens when the lungs suffer injury that triggers a strong inflammatory response and damages the alveolar–capillary barrier, leading to fluid leakage into the air sacs and severely impaired gas exchange. Aspiration directly injures the lung tissue: when gastric contents are inhaled, they cause chemical pneumonitis and damage the epithelial and endothelial layers of the alveoli. This increases vascular permeability, leads to edema in the alveolar spaces, and promotes the formation of membranes that hinder oxygen exchange. All of this fits the pattern of ARDS mechanism, making aspiration a well-established risk factor.

The other options don’t produce this kind of acute, diffuse alveolar injury. Hypertension, hypothyroidism, and seasonal allergies may have systemic or allergic implications, but they do not directly injure the alveolar–capillary barrier in a way that reliably precipitates ARDS.