Pneumonia exposure to cigarettes or air pollution, malnutrition, and poverty. The use of acid-suppressing medications — such as proton-pump inhibitors or H2 blockers — is associated with an increased risk of pneumonia. Approximately 10% of people who require mechanical ventilation develop ventilator associated pneumonia, and people with gastric feeding tube have an increased risk of developing of aspiration pneumonia. For people with specific variants of FER gene, the risk of death is reduced in sepsis caused by pneumonia. However, for those with TLR6 variants, the risk of getting Legionnaires' disease is increased. Bacteria are the most-common cause of community-acquired pneumonia (CAP),
Community-acquired pneumonia decreases with age until late adulthood, with the elderly at risk for CAP and its associated mortality. More CAP cases occur during the winter than at other times of the year. CAP is more common in males than females, and more common in black people than Caucasians. Patients with underlying illnesses (such as Alzheimer's disease, cystic fibrosis, COPD, tobacco smoking, alcoholism or immune-system problems) have an increased risk of developing pneumonia. CAP may be prevented by treating underlying illnesses increasing its risk, by smoking cessation and vaccination of children and adults. Vaccination against "haemophilus influenzae" and "streptococcus pneumoniae" in the