Why is bedridden person are susceptible to pneumonia than a patient who is ambulatory?

Bedridden individuals are more susceptible to pneumonia due to reduced mobility, which can lead to impaired lung function and decreased clearance of secretions. This stagnation increases the risk of fluid accumulation and bacterial growth in the lungs. Additionally, they may have weakened immune responses and may not effectively cough to expel pathogens, further heightening their vulnerability compared to ambulatory patients who maintain better lung capacity and circulation.